power amp question

I'm not familar with your Rotel but integrated units sometimes have PREAMP RCA OUTS/IN with jumpers installed. You simply remove the jumpers and insert RCA cables on the PRE AMP outs and run those to the amp you'll purchase.
As for amp - are you looking for tube or SS? What speakers are you driving and what power requirements do you have?

Yes, the 1062 has preamp outputs so using it as a preamp is as simple as using interconnects to go from those outputs to a power amp.

Why would you want to do that except for the fact that you don't have enough power for your speakers which I doubt, or if this is a temp. measure until you can properly update. If you want to update get a good amp and preamp.

What speakers are you going to be driving and do you want to try tubes?

I used my good Rotel RA-02 preamp outs when I first got a power amp. I was blown away by the change - esp in dynamic control - when I went to a dedicated pre-amp. So what you're suggesting is certainly OK but I think it would be an interim step for you.