This is how the metal frame looks like with the tracks:
Now it's time to install the new gasket which is just the reverse procedure as in the first post. I put a dab of w40 at the bottom of the tracks where the gasket will go in. Not sure if this is necessary, but a little bit of lub wouldn't hurt I though.
First slide-in the longest "rail" (left on the picture).
Then the right pulling up gently.
Then it's like sliding on a sock up (sorry blurry picture):
Gently pull-up making sure the two rails slide in the tracks. Massage the part up so to make sure it is up as much as it can:
Just a little more:
Done!
Now it's time to take care of the top of the gasket, starting with sliding-in the gromit:
Finally a dab of glue and you're done!
This is how it should fit with the window up:
