A lot of hits on the site recently from people with that search term.
Assuming you mean Warhammer Fantasy Battles, I’d refer you to Two Hour Wargames and their games Warrior Heroes ($25) and Swordplay (free), where you’ll feel right at home; very similar setting, same troop types (and the figures are the expensive part). Different rules though; the primary difference besides being solo is that the normal game turn sequence is replaced with something driven by reaction tests.
If you were looking for Warhammer 40,000 solo, you probably found my earlier post on that. I can’t be bothered to link to it, sorry, so short version: get yourself THW’s 5150 ($25) or Chain Reaction 3.0 (free) and the fan-created plug-in CR4104-v03.pdf (Google, and ye shall find).