I converted mine to tubeless.
Several layers of Electrical tape, and a BMX innertube cut to the width of the rim. Off the top of my head it took quite a bit of tape, so if thegreen tape is quite thick I’d leave that in and put the BMX tube/strip on top of that, try and inflate a tyre, if it goes up fine then you’re good to go, if not remove the cut down tube/strip and add more electrical tape.
The electrical tapes about the same density as innertube, I’ve done other rims by just building up layers and layers of tape untill the tyre inflates easily, a whole roll only weighs about 30g-40g, about the same as a Stans strip. Then just poked a valve (cut from an old tube) through and done up the locknut really tight.
I’ve not had much luck with the method of installing the split tube and tyre, inflating then trimming the excess, prefer to bodge a ‘stans type strip’ from the old tube first and install that.