This feature becomes an available option by finding and collecting ALL 6 secret eggs in Banjo-Kazooie and then going back to Banjo-Tooie and to Heggy's Egg Shed. At Heggy's Egg Shed let Heggy hatch ALL 6 eggs and you will be informed that Stop 'n' Swop II has been found.
There are 2 other Banjo Kazooie N64 game paks in the game. Both are located at spiral mountain. One is above where the tree stumps are. You have to shoot a grenade egg at it and then fly up there. The other is at the waterfall. You have to fly up into the cave where the waterfall originates. You follow that into a cave where there is a N64 Pak hopping behind a cage. Grip grab behind the waterfall in this room and follow that behind the cage. These secret game paks are used for unlockables in Banjo Kazooie: Nuts and Bolts
When you find Cheato on Spiral Mountain by entering the Witch's head one cheat will be revealed for every 5 Cheato pages that you find. Also hidden throughout the game are various mystery eggs which will reveal a cheat when you find them. Cheats are also given as rewards when you perform certain actions. When you have the correct amount of Grenade eggs enter the Mayahem Temple near Wumba's Wigwam and spell out the code to activate the corresponding effect. Note: cheats that are prefixed with CHEATO are unlocked immediately without having to collect the required number of Cheato pages.
Level Select: CHEATOJIGGYWIGGYSPECIAL
Infinite Health: CHEATOHONEYBACK
Infinite Air and Health: HONEYKING or CHEATOKCABYENOH
Infinite Eggs and Feathers: CHEATONESTKING
Infinite Glowbos: GLOKING
Infinite Mega Glowbos: SUPGLOKING
All Replay Sub-Options unlocked: CHEATOPLAYITAGAINSON
Jiggy Hints given by Signs in Master Jiggywiggy's house: GETJIGGY or CHEATOYGGIJTEG
Double Feather carrying capacity: FEATHERS or CHEATOSREHTAEF
Double Egg carrying capacity: EGGS or CHEATOSGGE
Eggs Home in on nearest Target: HOMING
No Damage when Falling: FALLPROOF or CHEATOFOORPLLAF
Banjo Moves Faster: CHEATOSUPERBANJO
Enemies Move Faster: CHEATOSUPERBADDY
Music Test unlocked in Jolly Roger Bay jukebox: JUKEBOX or CHEATOXOBEKUJ
All Mini-Games, Bosses, and Movies in Replay mode: CHEATOPLAYITAGAINSON
View Ending Sequence (only if you currently have less than 90 Jiggies): CHEATOJIGGYSCASTLIST
To unlock the signposts in Jiggywiggy's Temple, enter the code "GETJIGGY" (minus quotes) at the cheat temple bu Humba Wumba's hut in the first level. These signs tell the location of all the jiggy's in each world.
As soon as you enter Jinjo village, there is a place off to the left. There is lots of sand. You can jump up onto this ledge and do a high jump to grasp onto the higher ledge. Then, shimmy all the way to the end and climb up. There is then this little tunnel which you walk through and there is a little cave. There is a Banjo Kazooie N64 game pak in there which you can then get. P.S. You need to learn how to grab onto ledges from Jamjars before you can do this. You learn this move in the first level of the game, the one with the temple.