Vintage Dirt Bike Q & A

I have a new set of spokes and a new wheel which I am trying to lace up. I downloaded the instructions from the service manual and have followed it closely. I have the spokes laced on the large brake drum side, but am having a rough time trying to get the spokes in on the other smaller side. I can't seem to get enough give to shift the wheel enough to get the spoke to engage the nipple. It is a little to short. There must be some tricks to putting these things together. It's a 75 CR250. Any advise? Thanks, Mark