39-53t chainring on full suspension bike
The Giant Reign is a long travel 'enduro' bike that is designed to be ridden down steep technical trails, not pedalled down road/fire trail.

It's most likely that changing to a 39-53 will not work as the inner chainring will catch the chain stays, and even if it did work, it would compromise the bike in technical terrain, increasing the chances of 'grounding' the big ring on rocks etc.  You would also probably run into problems with the front derailleur as mtb derailleurs are not designed to work with such large rings, and the frame itself may not allow the derailleur to be mounted high enough to clear the 53t ring.

In addition, it would basically turn the bike into an 'uplift' only bike, as a 39t chainring would be much too large a gear for climbing off-road terrain.