Before I ask the SourceTree question, I have almost no knowledge of command line git usage although I can use SCCS.
The problem I keep running in to is I get to a point where my code is messed up that I just want to go back to the last good commit and start over. I might look at the abandoned code and copy and paste in the good bits later. What I usually do is click on the last good commit and pull it. This creates a detached head. To re-attach, I tag it (e.g. temp7) at which point I can now commit again.
This is obviously the wrong way to do it as I've long ago left tags: origin, master, temp, temp1, temp2, temp3 etc in the dust.
I just want my current commit to be the master. No merging, no reconciling, just take the current version and make it the origin/master or whatever it should be.
I'd read the SourceTree help but apparently there isn't any.