fader contacts

ok, now these little boogers are really giving me a headache, the little contact wipers keep springing off and get lost in the fader enclosure where they cause all sorts of trouble. What is the proper way to seat the contacts on the plastic mount? I have a feeling I will need to source some replacements for the little contacts, as they have become somewhat bent by my efforts to secure them. Or I might even have to look for new faders, but that will be pricey... please have a look at the picture below and give me a hint, thanks!!!

ok, three faders out now, can anyone give me some advice before I order three complete new faders?

thanks, Marten