Didds: 
  PROPER sports shops to put them on for a small charge 
  using a sort of cone.  You may be lucky similarly. 
  Other-wise roll the rubber up into a doughnut and then 
  FORCE the rubber over the end. Once you've actually got 
  the rubber over the end of the handle you just unroll 
  the rubber along the length of the handle and smooth 
  it down. It works well, especially with a twisting 
  motion with both hands using downward pressure towards 
  the bottom of the handle. 
  
Peter Watkins: 
  As it turned out, I actually got them on quite easily. 
  A (girl) friend of my wife got a disposable plastic 
  shopping bag, poked it through the grip, then used 
  the handles on the bag to pull the grip on the bat. 
  It went on reasonably easily.  Then I rolled the grip 
  from each end and cut out the shopping bag.