TB42 cam bearings

[Parksy]

G'day all

I'm currently rebuilding a tb42 and was hoping someone here has experience with replacing the cam bearings on this engine. They are largest in diameter at the front of the block and get smaller as you work your way back, so to me this suggests that they need to be pushed from the rear towards the front.

I'm just wondering if I need an expanding mandrel to pull them from the front or can I use fixed dies to push them out from behind?

Thanks all

Andy