I have a few enquiries about this roller bearing from my pm so I'll make a post here.
I'm not sure if the below applies to all daiwa reel or just some "real four" models.
But It is the same for my 1500, 2500, 2500R and 3500HD certate (04" model) as well as 2500R luvias.
the bearing size is the same for the a/m reels:
I usually buy a few pieces whenever I pass by the bearing shop. Kian Ho (Google it) gave me the best price. $3/-
I'll use the 2500 schematics in-order to explain better.
1) Remove screw (part no.22), the whole roller assembly should be separated from the bail arm.
2) There is this tiny C-shape wire or retainer ring (O-ring A part no.25: G47-1101 on your schematics) that is holding the bearing to the roller, that you need to dig out. The technique used here is the same as removing the retainer ring of the cover from a ball bearing, which I learn from alantani site (google it). I use a size 1 thin-shank hook to dig it out.
3) if you manage to dig out the tiny ring, the bearing can be push out from the other side.
Put some grease over it before you attempt to dig it out, this helps to prevent the ring from flying
Sometime I can get this ring out in less than a minute, but sometimes it took me hours