If you are worried about just the number itself, set the cluster to one of the trip meters instead of ODO, then reset the trip meter every couple of weeks.
Get a frame off complete car restoration, which could be up to $100,000, cheers.
It seems like you like your car and just want to keep it nice. First of all, it should be garage kept to protect the paint, fabric, plastic and so forth from the extremes of the elements. Secondly, you need to clean it and wax it and keep the interior clean. Also, you should use the best synthetic oil and a quality filter. I just did mine with a Pureone filter and Castrol Edge Extended Wear. at a cost of $32 plus tax. Keep up with all the maintenance and fix anything that goes bad and you should typically be able to keep your car for many years if not a decade or two. A nice, clean, well maintained car reflects well on it's owner and can be a nice asset to your life instead of going into debt to get something new before it's needed.
You could completely dismantle it and replace every moving part. Including a new speedometer (or computer, depending how old this car is) , Some parts for older cars are difficult to find.. It will cost like crazy. but there are some fanatics about this sort of thing.
Would you want to spent a fortune on a car with a tube type radio, bias ply tires , and maybe a 6 volt electrical system ?
If you are talking about changing the mileage history it is actually illegal in the uk and I suspect most places. Otherwise a rebore of the cylinders may help.
if I wanted to make my car almost like its brand new like get the mileage back down 0, how would I go about it? like what would I have to change to basically make it new again? I like my car is looks brand new, it drives like its brand new its just has too much mileage because I have to drive around 500 miles every 2 weeks