Make-up the guitar track and save (or export – your choice) a copy (give it a simple name e.g. ‘guitarsoloCopy’ )
Do your guitar + vocal tracks, and then -
Import previously saved guitar copy track.
Highligh the copy guitar track,
On effects menu scroll to ‘invert’ and apply.
Now mix the inverted copy guitar track with the vocal+guitar track.
Guitar now vanishes!
Points to note –
This will only work if the timing and levels of the guitar tracks (‘copy’ and ‘guitar + vocal’) stay identical – so no effects when putting the vocals on the guitar track.
This can be done in mono or stereo – your choice.