Gamer has been removed
Go to Contracts / Quick Play / Find Contracts.
Press Y or Choose Filter.
Change "Checkpoint" to Mansion Ground Floor and hit search.
They we're all pretty simple and self explanatory - just kill the targets and get to the exit. I never cared for any other optional requirements. Took me 10 minutes to get this done.
Easy examples:
3-0040--11864-drvx
3-0040--13670-fuck
3-0040--42226-tomj
3-0040--42290-gria