I have recently bought a Megane convertible and have 2 questions I would like to ask,
This is my first Megane so any help would be great

Firstly the gear stick knob is very worn and was wondering does the knob just screw off so I can just replace it?
I have tried to turn it and it does not budge but also I’ve not used real force just in case I damage it,
Also my car which has only done 67,000 miles runs great, but I have noticed with all this rain we are having that I have a slight leak driver side top corner. Leak as in drips!
Is there a way to check and possible unblock the drainage seal, as I’ve seen mentioned on a few posts? But no post or instruction to say how or where to do this?
Thanks in advance guys
Other thank that the car works great and great value for money