Step 1: Get some 25mm ID / 50mm OD bearings
Prise the side seals off and scoop out all the grease, then rinse the bearings out with some diesel or turpentine to make them spin easier, then pop the seals back in. They should spin easily now.
Head down to the hardware store and find a cheap broomstick handle that just fits inside the bearings. Dont worry if its a tight fit.
While you're at the store buy some 50mm (inner diameter) PVC tube and 2 large buckets (I found about 20 litres ideal).Also uy some long screws - I used plaster screws at least 50mm long.