Dear Kostas1:
The PIPE here once more...and I've been building ALL my own battery packs for almost THIRTY years now...!
About the BEST webpage I've found...that uses just about EVERY step I've always used...can be found at
http://members.aol.com/davthacker/cellsoldering.htm
...and I've recommended that page to LOTS of people here at RCU...no PHOTOS of the procedure there, though, but there SHOULD be enough text to get a REALLY good idea of what's involved!
Hope this helped...
Yours Sincerely,
The PIPE!