I have some 301's and 501's that needed re-foam. Fairly simple... There is a guy on ebay that will sell you exactly what you need. They are not generic kits but factory surrounds. Just take your time and follow the directions. One option is to find a pair of no name worthless speakers and practice so you are familiar with the process. That way you are comfortable when you start. The other is you can send them to a reputable repair person. I can send you a link if you are interested. They also have repair kits you can buy direct so you don't have to screw around with ebay.
Karl
Karl