I have a 2008 i just bought new and just tried the center stand for the first time this morning. I had a spotter because I wasn't quite sure how it was going to work out due to the weight of the GL.
First, I made sure the bike was in neutral. Then, I stood on the left side of the bike and put my left hand on the left handlebar. I put my right hand on the left handgrip for the passenger seating. I then pushed the bike into an upright position off the side stand and found the balance (which was surprisingly easy to do with this bike). Using my left foot, I pushed down on the center stand until it touched the ground.
Now, before I continued (and this is the critical part), I gently rocked the bike back and forth until I was absolutely sure that both feet of the center stand were solidly on the ground. NOTE: If I have ever had any trouble in the past with center stands, it is because both feet of the center stand were not solidly in contact with the ground. This can cause the bike to lurch or be too heavy to manipulate.
Once ready, and with both center stand feet on the ground, I stood up tall, pushing down with my left foot. I think the trick here is that you don't really want to lift with your hands and arms as much as you stand up tall with your legs. Your arms are more for stability than lifting, although you are pulling against the bike just a bit.
When I did this, the GL just jumped onto the center stand with very, very little effort. So little, in fact, that I was taken by surprise and my girlfriend commented that I had more trouble with my FJR than I did with the Goldwing.
I hope this helps, and if I'm not clear, please ask away and I'll try to explain better.