C/Y Carl Zeiss Sonnar 2.8/135 with stuck focusing ring

[blackpit]

Greetings from Greece!

new to the forum, although I've been a lurker for sometime now, and I've learned a lot of really interesting things! I've been lucky enought to have inherited all of my photographic equipment, except for the Canon EOS 1000D with the 19-35 lens, from my father who has been a long time amateur photographer and still shoots occasionally, when time allows him.

Introductions aside, I have a problem with the CZ Sonnar 2.8/135, AE version. The focusing ring is stuck. I've seen some of the guides on how to disassemble some CZ lenses and clean the focus ring with lighter fluid and regrease it, but couldn't find any guide for the specific lens.

I sent the lens to a camera repair shop here in Greece but they told me they have to brute force the lens because they couldn't disassemble it in a non-destructive way due to some metal part floating and having stuck the focus ring. From what I read, I just think the grease is to blame, as it's 30+ years old now, but I can't know for sure. The lens has not been mishandled in any way, nor dropped or anything like that.

So, how easy (or difficult) would it be for me to try and disassemble it myself? I have no prior experience with this kind of stuff, and truth is I am somewhat afraid I could damage it further. Any chance it could get better if I heated the lens somehow (my oven can hold a steady temperature). If i choose a professional service to do the repair, would you know of a knowledgeable technician, preferably in Greece, or even in another European country? Perhaps Miles from mwcamerarepairs.co.uk also does lens repairs?

Any suggestions are welcome!

Thanks,
Panagiotis