Here's an exploded view of the Model 31:
http://www.again.net/~steve/ipb-remington-31.html
Here's disassembly for the Model 31:
Open action and unscrew the barrel lock nut (part 15) to the left.
Turn barrel 90% to the left and remove it forward.
Push out trigger plate pin (74) from Right to Left and turn gun bottom up.
Slide trigger plate (42) forward until trigger plate studs (48) align with slots in sides of receiver. If gun is cocked, press action bar lock (56) to release trigger plate before moving trigger plate forward.
Lift trigger plate out.
Lift out left and right cartridge stops (39 & 40) from inside receiver walls.
Move fore end (81) rearward until projection at rear of slide (68) is even with trigger plate holes in receiver sides.
Pull upward on slide while moving fore end forward to free action bar (12) from slide.
With fore end and breechblock fully forward, swing front end of carrier outward until about perpendicular to receiver and press ends together to disengage pivots.
Lift the carrier out.
Press ejector (37) fully into it's slot and lift out breechbolt.
Swing ejector rearward and lift from it's slot in the receiver.
Drift out the firing pin retainer pin (73) from Left to Right, and remove firing pin (750 and spring (76) from back end of bolt.
Drift out extractor pin (78) from bottom of bolt and remove left extractor (79) and spring (77).
Insert small screwdriver in back of right extractor (71) and pry back extractor plunger (69), then push screwdriver forward, pushing extractor out of slot.
Remove extractor plunger and spring (70).
With hammer (57) in fired (forward) position, drift out mainspring pin (46) and remove safety spring (44) and safety plunger (43) from lower hole.
Remove mainspring (64) and mainspring follower (63) from upper hole.
Remove safety (45).
Drive out hammer pin (59) and push hammer forward and down until rear of hammer link (62) is out of slot in trigger plate.
Pull hammer link rearward disengaging hammer from action bar lock spring (55).
NEVER LIFT HAMMER UPWARD UNTIL IT HAS BEEN DISENGAGED FROM THIS SPRING OR THE SPRING WILL BE BENT OR BROKEN.
Lift away hammer.
Drift out trigger pin (60) and remove action bar lock with spring attached.
Trigger lock plunger (53) and trigger lock spring (54) may be removed.
Rest of trigger plate disassembly is obvious.
Reassemble gun in reverse.
When reassembling mainspring, mainspring follower, safety spring, and safety plunger, it is easier to insert these parts first, then after replacing the mainspring, use a short wood dowel to compress the safety plunger.
Then reinsert safety.
This is the reverse of what seems obvious, which is replacing the safety THEN the spring loaded parts..