radiator expansion tank - has anyone replaced it or just the seals on it?

[Cobra Jet]

I just noticed this morning that my radiator expansion tank is leaking at the very bottom where it meets the radiator (where the seam is above the small lower hose).  It seems to leak more when it is cold out, but once warm it seems to be ok or not leak as much.

When looking online for a new radiator on bimmerparts.com, they don't stock the radiators for the 91 318's, however, I did see they sell a brand new expansion tank w/ upper & lower seals for about $32.00 - OR they also sell the expansion tank upper and lower seals separately too....

I did not know you could replace just the expansion tank...

Here's my questions:

How do you replace just the expansion tank, or how to remove the tank just to replace the seals (has anyone done this)?

Should I just buy a complete radiator instead of replacing just the expansion tank (and who sells a 318 radiator for a good price)?

My 318 only has 117k on it and the radiator is not seeping or leaking from any other area at all...  only the expansion tank is leaking at the bottom...

[tjts1]

Search for the thread titled "tjts1", my SN. There is a post in there where I fixed the same thing with some silicone sealant. Good luck