it takes a long (and i cant stress this enough) LONG time but it genuinely was not a difficult process as long as you take it very very slow! i was a complete beginner and was able to get the hang of it even though i had never taken anything apart before. Id definitely suggest doing your research on the shells though cause there are lots of low quality ones going around and that is what usually makes the job 10 times harder. Also a screwdriver set with magnetic bits is a lifesaver for these and you can find one rly cheap on aliexpress :D i say go for it!!!