Yep the rear can be lowered in theory fairly easily, the only problem you may come across is the torsion bars being seized into place, these can be a pain to get out but with some persistance, plenty of lube and one of the recommended methods itll all come good in the end.
With the front you can just change the springs if you wish, however if you're going to lower it more that 40mm and intend on keeping the car a reasonable length of time you may want to upgrade the shocks aswel and buy the full kit on the front, id certainly recommend that