I have a 2019 so I'm not sure if certain parts are slightly different. I used 2nd Chance's parts list to do my conversion as well.
If you get the TRD skid plate, you don't need the lower radiator air dam valance and OEM skid parts (52129-35030 and 51450-6005). You will need to remove your old radiator deflectors regardless and add new ones (53293-35020 and 53294-35020).
See below for the list of parts that I used. Some of the part numbers for clips are the same throughout so the names may be arbitrary. Also some of quantities for the clips (75392-35220) are wrong depending on whether or not you want valance trim from the Off-Road or Pro.
The reinforcement bar components are not included below. The limited uses a different bar so it needs to be replaced. I highly recommend you try to find a complete reinforcement bar set for sale used, it saves you a lot of time and money. There are a number of parts you need separately otherwise and they add up in cost. I picked up a complete set for ~160.
You'll also need the bumper. If you decide to get a new one, just get the OEM one and do not save money on this part.
Part Number Part Name
90467-07201 Fender Liner Clip 5
52116-35140 Bumper Cover Retainer 5
90467-05138 Bumper Cover Retainer Clip 2
90159-60215 Fender Liner Screw 2
52127-35100 Fog Lamp Bezel 1
52128-35080 Fog Lamp Bezel 1
75392-35220 Fog Lamp Bezel Retainer 20
52114-35040 License Bracket 1
53112-35060 Lower Grille 1
52134-35070 Retaining Bracket 1
52133-35060 Retaining Bracket 1
52148-35120 Stopper 1
90467-07211 Sight Shield Clip 5
53293-35020 Deflector 1
53294-35020 Deflector 1
53875-35150 Fender Liner 1
53876-35150 Fender Liner 1
90189-A0002 Fender Liner Grommet 4
PTR60-89190 Toyota 4Runner TRD Front Skid 1
53101-35080-B0 (SILVER, 2019) [different than 2020] Grille Assembly 1
Hey - I'm new to this forum and have read a ton of your posts. Thank you SO much for the great detail on the Limited to TRD swap! I just traded in my 2010 Limited with 250k miles for a 2020 Nightshade (Limited). I'm trying to make the front bumper swap to a Venture (SR5) as soon as possible, so my stock bumper can be sold in stock condition. (See image below for my current swap plan.)
I wanted to see if you ever updated this parts list with the 4 remaining parts. I know my parts will be different, but I'd love to have this as a base. Also, if you happen to have it in a spreadsheet format instead of a PDF, that would be incredible! Thanks again.