I uploaded the instructions I followed.

Basically when I edited the Advanced Properties, instead of a prefix of -m; I used a suffix of ; sqlcmd-m

then I didn't actually have to login, I just need to access the instance through the command window opened as Admin

then after I created the login on my own windows account, I added the sysadmin to it using sp_addsrvrolemember text, I fiddled with until it worked.