Convert Auto to Manuel Trans......Anyone done it?

[Bodyguy]

Hey guys,
I am brand new here and I do not own a supra. However my father-in-law does and he asked me to look into converting his 89 Supra turbo targa top into a manuel trans car. So that brings me here. I hope you can all help as I don't know a lot about the cars and what is possible. I am a bodyman by trade and have full access to a hoist and every tool you can imagine so that is not an issue. I want to know what we need to do the swap. Has anyone had success with it? Anytime I have ever spoken to a mechanic about converting a car to manuel from auto they always say don't do it, more trouble than its worth, etc,etc. But I have found through some other projects that it is a bit of a job but its not as bad as it seems and sometimes I think they say it cause they don't want to be asked to do it. lol. The only car I have seen have a problem was my buddies 89 T-bird. It would only start in neutral, thats it. This car is mint. It gets driven about twice a year and has less than 100,000 kms on it. Full leather, white, nice car. Thank you for all your input. Also budget is not necessarily an issue. So if there is an aftermarked trans out there that is a bit pricey but awesome then let me know cause its worth saving for in my opinion.Thanks again!