Have fun haha. Gaskets are pretty straight forward. The coolant pipes are too if you have ever changed your coolant before. If not its just draining the coolant, replacing the hoses, then refilling and burping the system properly. Make sure you use a bottle of the subaru coolant conditioner as well, it is a must if you don't want leaks.
The turbo inlet is going to be a royal pain though. Its a process, best to find a write up on it, you might want to look at other mods involved with taking off the intake manifold, like TGV deletes and replacing TGV to Intake gaskets and TGV to block gaskets, might as well while you are there. Fuel pump is pretty simple too, nothing tricky.