These JR kits do not need the trans removed for installation....
However....
They will not correct worn bushes, clutches and bands or worn pump housings.
You must follow all instructions and perform all steps....then tune the TV system as directed in the installation instructions ....
The kit includes a paper install instruction set, but here is a link to the online PDF file you can review prior to purchase...
https://res.cloudinary.com/transgo/wbiss/sk/SK700JR.pdf