I started tearing down my M2S4 Manual transmission and found that the Snap ring on the Idler shaft has one of the ends missing. I cannot easily expand it to remove the transmission casing. This could be the same issue with pretty much any D,B,F,H manual transmission. An suggestions on how to get the transmission apart?

I fought with it for a good hour last night, I was able to get at least one side bent slightly but not enough to separate the transmission from the casing. I'm thinking that I may try to get some channel locks attached to the darn thing and brute force it out.

 

I was able to get the vice grips connected and pull it out. M2S4 transmission looks clean except the 1st and 2nd gear synchros look a little worn. When I bought the transmission I was told that either 4th or 5th was starting to grind a bit. I pulled apart my Old Accord Transmission(P2U5 I believe) to see the damage and see if I could salvage anything, 4th and 5th gear were pretty much toothless. haha. I did see that the synchros looked pretty good. I was looking to buy some new synchros for the M2S4 but it looks like they are the same part as the P2U5. I think ill pull the ones from the Accord transmission.

I am still doing some reading but I have to assume the b-Series transmissions and H/F Series have the same gear layout. Can anyone confirm that?