Capacitor replacement techniques. Opinions?

[Eric H]

I always desolder and remove the old cap completely, unless like Arkay said if it's really, really difficult I will snip and solder onto the old leads, (i.e. if the risk of breaking something is too great to completely remove the old cap).

On rare occasions I'll melt out the old caps guts and install the new one inside the paper shell, using paper washers on the ends and hot glue to simulate the wax filling.

Electrolytics get stuffed into the old can whenever possible, if I can't get them all inside the can I'll do what I can and stick whatever I can't underneath.