Push/pull to create the gitosis repo/update the branch info.
git push origin master;git pull
Track the origin branch
git branch --set-upstream master origin/master
On the gitosis host, find the new repo, and cd into its hooks directory
Create/edit post-update with this line
ssh ikiwiki@<ikiwikihost> ./update-iki
AKA, the same command you ran earlier as gitosis
Make post-update executable
At this point, you should be finished, try adding/editing a page to make sure it all works
If it doesn't work correctly (mine complained that an index.html file had been created independently so it wouldn't kill it), try removing all the wiki files again (keep the cgi file though) and pushing a commit through gitosis.
Update the historyurl and diffurl variables (can be done in webconfig)