This is how I removed the idler bearing, and is very easy to do, Just imagine that the bearing in the casing 
First Knock out the rollers and cage by sticking a screwdriver between the cage and bearing body.
Then got a longish bolt, A few thick washers, one needs to be the internal diameter without the rollers to be able to grip the lip, then 2 sides need to be cut and filed to the inside lip diameter of the hole like the picture below.
it can then be put on the bolt and slid into the bearing, Bolt smaller thick washer, thick cut washer.
then get a plate/bar to got over the caseing and wind the nut with a few washers onto it, you may need to put a spacer in like my pic.
It may not feel like it's coming out, it will after a while and maybe with a bang...
