#1
Can I just change the strings to a higher gauge ones, and done? or will it require some adjustments? will it damage my guitar?
#2
Provided you match the string gauge to the tuning, it should not damage the guitar. However problems I can see are:

The nut and saddle or bridge pin slots might need to be widened.
Intonation may be sharp with heavier strings. - I just had to do some major work on my uke when I went to heavy strings for down-tunings.
It may sound dull and flubby. Not many guitar take well to low tunings.
Last edited by Tony Done at Oct 31, 2016,
#3
Quote by Mr. Cachi
Can I just change the strings to a higher gauge ones, and done? or will it require some adjustments? will it damage my guitar?


It depends what sort of sound and playability you wish to achieve. The temptation (for logical reasons: equality of tension, etc) when down-tuning is to go for heavier gauge strings and you can certainly do that if you want although you may encounter some or all of the problems that Tony mentions (in my experience poor intonation on the bass strings, especially the 6th, is the biggest problem).

Or you can stick with light or medium gauge strings and just tune down. The guitar will certainly sound less bright but will be very playable due to the reduced tension (and with the reduced tension you may need to tighten the truss rod a little to compensate - but perhaps not - try it as it is first}.
.
I keep one of my acoustic guitars (Recording King 000 parlour) permanently tuned down to standard D. That's low enough for me (although I often lower the 6th string - and sometimes also the 1st string - by two semitones to C to get "drop C and double-drop C"). The strings on the guitar are just regular 12 gauge 80/20 bronze and, for me, they sound fine for standard D. If I was going to go as low as standard C I might use 13's - but no higher.

As always, these things are subjective. Experiment!