i took the rad off my old abarth just yesterday mornin! u can do it without takin the bumper off but it becomes 200% easier if u do.
basically there are 2 pipes running to the right of the rad, both with jubilee clips that need to com out, when u do the bottom one b aware that the coolant will com out if u hadnt already drained it!
there is also a little pug in the middle of them that needs to com out as well, just give it a pull!
next u need to pop the bonnet an have a look down in front of manifold, there are 2 bolts (10mm i think) that support the right hand side of the rad that need to com off.
then u need to disconnect the fan motor switch it is behind the fan under the drivers wheel arch (u may been to take arch liner out, mine were already out so aint 100% sure)
then it should slide down and to the right if u are lookin from the front of the car, however it wont com all the way out, there are 2 cable ties that u need to cut, and behind the drivers headlight there is another little pipe with a cross headed plug on it, unscrew the plug, with a little fiddling the rad should just slide out.
much much easier with the bumper off as u can c the whole rad an the area u are workin on!