Here are some suggestions of finding parts for record changers, needles, idlers, and cartridges.
http://www.thevoiceofmusic.com/catal...no_needles.asp
http://stores.ebay.com/CAROLES-NEEDLES Also there are many other sites as well.
Remove the cartridge and there should be number and make on it like EV, Tetrad, Ronette, etc. You can then search the web or these sites and find the correct needles and or cartridges. Also look for the make and model of the record changer. Most likely as it's been sitting for a long time, the rubber idler wheel and motor grommets will be hard and may need to be replaced. Also get some denatured alcohol to clean off all the old gummed up grease on the changer mechanism, etc. You may also have to take the motor apart and clean the armature shaft and bearings as they are also probably dried up, slowing the motor down, maybe even causing it to freeze up. (motor should spin real easy and free). Clean and lube the spindle bearing as well. Just remove the small C clip (at the bottom of the spindle) that holds the turntable in place that keeps it from falling off. I usually re-lube with lightweight turbine oil, or you could use another light weight oil or grease. I usually find that oil works best for me. Pay close attention to all the small parts, take pictures and don't lose any small screws, C clips, etc. Record changers are pretty easy to fix, just take your time,