Broken RCA jacks

Pay someone to do it....

Radio Shack sells generic replacements. A lot of times they are in stock in the store, so you don't have to wait for the mail. They do ship to your house or your local store.
http://www.radioshack.com/search/index.jsp?kw=rca+jack&f=Taxonomy%2FRSK%2F2032231&categoryId=2032231&kwCatId=2032058&cp=2032058

A set of tiffany style jacks is indicated. Soldering is not that big a deal. One of the mail order houses like http://www.musicdirect.com would be better.
You'll need a good soldeing iron and some silver content solder. Practice first. Remember to heat the joint first then solder.

For Nefarious reasons the Jack is always abutting a fragilge old silcon trace board that is soldered in place and cannot be removed. Therefore I second the let some else do it idea .

If I'm not mistaken, you probably have a type of RCA jack in which the outer ground is a "sleeve" that snaps in place. I once had an amp that used these and they would come out if your cables were too tight.

If I'm right - the easiest fix is to find some spares outer sleeves. It's possible you may be able to find this type of RCA jack and radio shack, but I doubt it. You'll probably need to cannibalize them off of a similar receiver or other component from the Receiver's manufacturer. Shop Craig's list and local thrift shops for a parts unit.

Another option is to cannibalize them off the same receiver. I can't recall ever using all RCA inputs on any receiver or preamp I've owned (except on that only had 2 inputs. So, if you have 2 different inputs each missing one sleeve, pull one out from one and install it in the other. You may want to add a dab of superglue when you install it so it doesn't pull out every time you remove cables.