The Back In Time Equipped Glitch (BiTE) is a trick that allows you to warp to the first King Bulblin Fight like the Back in Time Glitch, but allows you to use the items obtained from another save file.
It's important to note that the success of the Back in Time Equipped Glitch depends on the state of the area the savefile is in and the spawn point ID that is being loaded in, for BiTE to work they both have to exist in the eldin field map as well, the room ID of the savefile being used also has to be 0 as that is the room ID of the Bulblin map
The state for phase two on the bridge for Bulblin 1 is state 4, if you do BiTE with a savefile in state 4, along with a working spawn point and room ID 0. There are only two known locations where this is the case, the first being a savewarp in the cave before entering Goron Mines After Temple of Time, the other being savewarp in kakariko after wagon escort and making zora queen go into the graveyard so the savewarp spawns you by the pond. In 100% The location in the cave is used to skip the field fight as it is also possible to get BiT very quickly from the savewarp location. All that is required upon the savewarp is turn around, LJA over the trigger and jump attack into the void to get BiT.
After getting the iron boots, save in Mayor Bo's House. Go to the Ordon Ranch, and immediately after Link stops moving, turn around and use a Long Jump to get over the loading zone. From here, roll about 3 times and do BiTE. This will automatically warp you to the King Bulblin battle. Obviously this faster spot for BiTE can't be done on the Wii Version, so instead, BiTE would be done from the bridge to the Faron Woods for the Wii.
There is a set-up that uses shield bash after the LJA over the loading zone which can be buffer and hence a good alternative. To do this stand just before a white spot on the wall shown in the video which is near the edge of the physical ground, then line up your first heart between the two poles, finally press R and D-Right at the same time to buffer the shield bash, now zoom out once and then press X-Start-B (With B being the last button)