I didn't have much problems reassembling the MacBook. Thanks a lot!
For the hard reassembly part with the clips: I pushed quite hard with both thumbs directly over the place where the clips are. You need to figure out exactly where they are, but it worked well.
I repeat it to make it clear: I pushed from the top on the location under which the clip sat, with two thumbs after having checked that the lid was well in place.
My tools were one spudger and a basic tech toolkit from iFixit.
Thanks a lot!