Were can'i buy parts to make my car with steering wheel in the other side?

if there is an opposite hand version in the manufacturers range you can buy most of the parts, but unless you buy a new body shell you will have to cut and weld for things like the pedal mounts. You will also have to do SVA approval to register the car in UK, and it will be next to impossible to insure. Just sell it and buy the car ready made as you want it - much easier

this is more involved than You may think. dashboard changes.wiring changes. steering rack .bulkhead etc will take many man hours and a heap of cash but all parts will be available from a main dealer ( unless that Model no longer made) even a breakers yard can often be a good source of supply. not a good project and especially not for those with little idea of what is involved.

New body shell, new steering rack (Complete), new dash, you will also need new pedals as well plus loom and much, MUCH more. Cheaper to buy a new car than convert an old one.

You cant, it was either built that way or it wasn't, sure you can buy parts but that dosent mean they will bolt up to your car,

Forget it, if it's possible at all it'll cost several thousand pounds.