Advice / tips on moving from center/guard to tackle.?

Hi folks, a little advice needed. I play American football here in Australia and I've played center for the last 4 years and done pretty well, but this year coach has moved another guy into the middle and I look like I will be moving out to guard or tackle. Guard I can handle, I started there and it's not that different to center anyway, I can pull, cut and everything else I need. But I am a little concerned that I'll be playing catchup at tackle (it seems so wide open!).

Specifically, I've been working on what my coach calls a 'drag step', which I just don't seem able to get. It's a little hard to describe, but effectively off the snap you move backwards from the line of scrimmage (as if keeping tabs on a wide pass rusher) head and chest up, hips low, and you keep your inside foot on the deck, dragging it as you move backwards with most of your weight on your outside leg. The idea being that you can keep an eye on the outside guy, but still be ready to front up to a bloke who tries to come through your inside gap.

It makes perfect sense when I see the other linemen do it, but I can't for the life of me get it to work (too old to learn new tricks maybe) so any tips from someone who knows would be great.

Thanks guys