Its really simple to do gforce. Take out the old stuff and really is just a case of tracing and cutting then super gluing it back in. As for the palm on your blocker if your already handy with a needle and thread that pretty straight forward too.
Apparently Nash Sports are a good source for replacement thing like blocker palms, foam and the sorts. I'll try and find you their email as i dont believe they have a website.
EDIT
Found their details;
NASH SPORTS MANUFACTURING LTD.
R.R.#1 Lakefield Ontario K0L 2H0 Canada
Tel: 705-657-9420 Fax: 705-657-1325
nash@pipcom.comHeres their web page as well but its not too great;
http://www.pipcom.com/~nash/