Yes it fits.
Just need to use a modifed SW20 gearbox, as you obviously cant make the curren 4WD.
(well, unless you have access to Scrooge McDuck's vault)
Celica and currens are virtually identical, well the NA ones anyway.
As for
easily....
That depends.
IF you have a million dollars, and want to pay someone to do it, then yes. it is very easy.
If you want to do it yourself, and have no idea what you're doing, then it's very hard.
However it is definitely feasable.