I'm a bit late to the party, but added this post for reference to others who may be thinking of doing similar.
I do have experience of doing this with guitars, but this is my first bass. I am always browsing new Chinese hardware that comes out for guitar conversions when I came across this on Temu:
A couple of problems with doing this conversion in trying to avoid routing the body. The string height of the bridge saddles has to be close to the original bridge, and the tuning pegs need to be clear of the body. The design of this Temu bridge fulfilled both these criteria. Using something like the Steinberger style bridge, which had a saddle height of nearly 20mm, would have required routing or a severe neck offset.
At the nut end, the hardware was a perfect fit. Also 2 grubscrews per string and no grooves weakening the threads. The hardware was advertised as 'high quality'.....hmm, always a risk for goods made in China, but at £43, I figured I would take a gamble.
Took a week to arrive & I set straight to work. First thing is to line up bridge so its straight and the bridge saddle position lines up with old bridge. There is a bit of leeway, and I bore this in mind. I needed the bridge to be far back enough for tuning pegs to clear body. As it happened, everything lined up perfectly:
At this point I could measure the string saddle height. Compared to the original saddle, the string would sit 3mm higher (16mm total). This could be a deal breaker for me, so I roughly anchored the bridge with an existing screw hole and installed a string. The action was too high, so I shimmed the neck with a piece of Amazon cardboard envelope and this brought the action right down. I knew this was rough and the final shim size would need to be adjusted with all the strings installed & under proper tension.....but at least I knew it was do-able.
So I proceeded with mounting the bridge and screwed into place.
The nut end couldn't be easier. Removed the truss rod cover, positioned the nut hardware, drill 4 holes & screw in........done!
Before chopping the headstock off, I strung everything up to check string height. With the cardboard shims, the action was slightly high. I replaced it with a plastic credit card shim and that did the trick. Perfect.
I proceeded to chop the headstock off, a bit of sanding and wax polish and the conversion was done.
The whole procedure took a couple of hours:
A few more pics:
The only negatives were the screw sizes provided were either too long or too short, and the bass now sits on the tuning pegs if leaned against the wall. Its fine in its stand, but if I was using the floor I would use a longer screw and space the strap button maybe half-inch so it took the weight. I also would have preferred black hardware, but this was sold out. Other sellers had black in stock, but it was 2x the price. Now that I know it works, I might have paid it, but at the time, I didn't want to gamble that much.....
All in all, an easy conversion!
UPDATE:
My OCD was getting to me. I spaced out the strap button: