Upvote:2
There is a transfer bus provided for transfer between Terminals 2 and 3, both ways - the transfer is advertised to take around 40 minutes, but usually completes in less than that.
Having just transited Dubai Terminal 3 in the past 2 weeks, I can assure you that there is ample signage for the Terminal 2 bus transfer, and there are many many manned help points where you can be pointed in the right direction.