I picked up an old acoustic steel string from a thrift store, its in good condition, tuning pegs and bridge are all excellent working and all, but the guitar had really bad old string on and the action is is high. I've taken the strings off and replaced with a new set, I've used just the 6th string to gauge how bad the neck and intonation is. I've never adjusted a truss rod beofre so want to make sure it's what's needed and and some advice welcomed.
I took some quick pics to demonstrate. The distance between the 12th fret and the string is 8mm while the distance between the nut and 1st fret is 3mm. Obviously the distance at the 12th fret is very high and needs to be lowered.
Is this correct and if so, how do I adjust? if not, then what can I do to rectify this problem?
Pic 1:
https://ibb.co/gFDSm0S
Pic 2:
https://ibb.co/QMHwcwH