http://www.picbasic.co.uk/forum/showthread.php?t=543

What it boils down to....

Method one:
Comment out the config settings in the inc file, put the actual config settings in your source code prefixed by either an @ or inside an ASM block. Use this method if you frequently change this setting or that setting a lot.

Method two:
Comment out the original config settings in the inc file, add in your own config settings to that same inc file in the same place. I use this method since I almost always use the PICs in the same way (i.e. HS_PLL for the 18F, MCLR on, and so on and so on)

Method three (and others)...
Lots of different methods for doing this sort of thing. The 2 above are the 2 that I use.

Check the particular PICs .INC file in the MPASM directory for your particular PICs various options...