change the properties of a grace note?

I'm new to the software, so not sure if my question has been answered already (googling brings me nowhere so far) or what sub-forum it belongs to.
I have imported a score from guitarpro, and it has a lot of grace notes that should be acciaccatura. They are, however, imported as appoggiatura. Can I select my incorrect notes and turn them into correct ones? Right now the only thing the software allows me to do is create a new acciaccatura right in front of my appoggiatura. That seems a pain in the younameit, as I need then to delete my initial grace note and make sure the new grace note is on the correct line, which is my second issue with musescore. Can I force a G# to be displayed as a G# instead of an Ab? The workaround I've found is move the pitch a half-step down with the arrow key (the Ab turns to a G natural) and then back up (it goes to a G#), but it's mildly annoying. I don't want to leave it displayed as an Ab because it's a grace note in front of an A natural, which then comes with a cancel sign...
Thanks and sorry if I'm just being stupid or blind or unable to google the answer