Next is the front or "bell" housing. Remove the thrust bearing and clutch fork if not done already. This gives unobstructed access to the transmission front cover:
Undo the six bolts holding the cover in place. Be sure to keep track of any shims that may/may not come off with the cover. Be careful, the shims are very thin and can cut.
Assembly note: these shims are important as they set the forward bearing clearance (see FSM). Do not lose them!
Underneath are the two forward bearings: maintshaft on top, countershaft on bottom.
Note the c-clip rings on the mainshaft bearing and input shaft. These both need to be removed before the bell housing can be removed.
Note: Here is where some variation can occur. My original transmission had a small c-clip ring on the countershaft in front of the smaller bearing. The Miata countershaft I used to replace my original did not use a c-clip hence why it's not shown above. Make sure all c-clips are removed from the bearings and shafts before attempting to remove the bell housing. Also the bearing may or may not have "dust" covers like those shown above.
With the front cover and all c-clips removed the bell housing can be pulled off the rest of the assembly. Like the extension housing it is sealed with RTV so it'll take a few hits with a rubber mallet to break free. Depending on the age of the transmission the bell housing may slide right over the bearings or it could require some coersion. This is what's left:
Ignore the plug in the image above. The next step outlines the removal of the 5th/reverse gear housing, shift rods, and shift forks.