Jolida 302 convrted to a 502?


I have a Jolida 302 that came trashed from shipping. I have it working fine but I'd like to up the output. The pro shops offer an upgrade that does little more than change 4 resitors and 4 tubes. Of course they are not forthcomming with that info. Can any one walk me through this? I posted once before but got no responce.
lpont8fc
Thanks, I have the schematic. Its the same with some exceptions, none of which I can recognized. Please e-mail me and with your generous help I may get through this. I'm at ponterio22553@yahoo.com.
well, I tried to email you off-line & I got this error message:-

554 delivery error: dd this user doesn't have a yahoo.com account (ponterio22553@yahoo.com)
Unable to deliver message to (and other recipients in the same domain).

What gives??