Wanna know how to *completely and utterly* destabilize a nation, wreck the social landscape and break the spirit of its government? It's a deceptively simple trick. There's a lot of risk involved, but then again any proper action against a tyrannical foe is a high risk affair. Just read on.
Before you start, you must already have a compiled list of targets you would like to see dead. This is because this method will involve murder, and quite a lot of it. Better be people you wouldn't mind dying, no? Open borders activists, socialist pundits, journalists, politicians, they are all fair game. Don't pick too hard to reach targets though, you don't wanna get caught and especially not early on.
Alright, you have your target now. What you're gona do now is use all your learned skills to quietly break in, sneak into the target's bedroom and murder him in his sleep with minimal fuss. This is important, you want to make as little noise as possible to buy enough time to prepare the staging grounds. What does that involve? Simple, rig all entrances to the house with lethal booby traps, preferably bombs for their unmatched destructive potential and consequent psychological impact. You're also going to prepare a lure to make the cops come and investigate. I personally suggest a time-delayed audio recorder with mini-speakers to broadcast blood-curdling sctreams, but whatever floats your boat. Once it's all set, get the fuck out and put as much distance between the booby-trapped house and you as possible. When cops kick the door in, they'll be greeted with a huge explosion that will send them to kingdom come.
Next morning, when you're watching the aftermath on the news, you will prepare your next target. Come next week or next month or whatever, you do it all over again. Don't let too much time pass, you want to keep up the pressure. Pick a new target, kill them quietly in their sleep, set up lures, rig up bombs, leave. The same thing will happen. Repeat the steps a few more times. Sure, come the second or third time this happens they're gonna send the SWAT and/or the bomb squad, but those are high-maintainace and even though the government has virtually unlimited resources even they have a limit as to how much they can piss away at once. Simply put, they can't send the SWAT or the bomb squad or the National Guard to investigate every break-in. Sure, they'll also impose draconian measures such as curfews, patrols, random checkpoints, state of emergency, and so on. But again, *they can't be everywhere*. The power of a government is mostly psychological in nature. This is what your real target is. If you undermine the state's image of an all-seeing, all-powerful entity, you're left with an ordinary bunch mostly composed of badly trained half-wit thugs protecting feckless bureaucrats. This is the one loss the government *can not* shrug off. It's crucial that you understand this.
Don't even get me started on the psychological damage you're going to wreak on the goons themselves. As another poster here put it, you need police to enforce a police state, and while government thugs are brave and cocky against an unarmed populace they'll be quaking in their boots at the mere thought that they could be blown up the next time they kick in someone's door. Do this enough times, the cops will be too scared to investigate *any* crime and simply piss off. Eventually, they'll be content to just protect the elites because it'll be "safer". Big mistake. This will only speed up the process. A population that is left defenseless is a population that grows restless. Sure, it will take a while for the message to sink in (I would cite the UK, but there's cultural factors that skew things a bit). When crime is at an all-time high and the government isn't even *pretending* to protect its constitutents, it's inevitable that the people will become angry and decide to take things in their own hands. A person with a strong mind and charismatic outlook will have an easy time seizing the people's anger and focusing it on the elites that have abandoned them.
That's the easy part down. Whatever happens next, is up to you. Good luck.