You can probably just un-clip the fans and put them the other way without removing the heatsink? Well, if the temps are okay, then there's nothing wrong with the paste.
edit: Also put the RAM modules to the correct slots (A2 and B2)
I think I did, put the matching ram in the coloured slots. I'll send a pic when I've done the fans.
Edit: So I had to take the cooler off because the idiots thought it was a good idea to put one of cpu fan's cables under the metal bars. I discovered that they had put a ridiculous amount of paste on, so much so that it was leaking off the sides. I had to use an ancient surgical spirit as alchohol but unfortunately, I couldn't get it all off. Some of it is stuck on the green part almost under the metal part. No matter my efforts it was impossible, though I minimized it as much as I could. There's a small line of it stuck in the crevices of each side of the cpu's metal part.
Luckily, the paste I used (and that they hopefully used too after I gave them it and they said they would) is non-conductive. So I'm letting it dry for an hour and hopefully I can reapply and everything will be fine. I just really hope this doesn't affect performance or temps, even slightly.
Edit 2: I used an old toothbrush and it worked well, there's still miniscule slithers visible at an angle on the green and metal parts, though not much at all. Just waiting for it to dry now. Still worried this could cause some issues, even small?