How i can pump a flat tire on my 200e razor scooter

That is a complicated system. Just take it into a local cycle shop.

https://razor.com/products/electric-scooters/ecosmart-metro-electric-scooter/#

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https://www.youtube.com/watch?v=nu8TbterSqs
https://www.youtube.com/watch?v=nu8TbterSqs
https://www.youtube.com/watch?v=U5bLxlCmKRU
https://www.youtube.com/watch?v=IpLxb4TneBk

1. rotate the rear wheel until the hole in the sprocket lines up with the tyre valve.
2. insert the tyre valve extension through the hole and attach it to the tyre valve
3. inflate the tyre to the correct pressure (usually 45psi)
4. remove valve extension and put in a safe place for next time.

Inflating the rear tyre is detailed in the owners manual, which you can download from the Razor web site.
http://www.razor.com/au/products/electric-scooters/e300/

using a Normal bicycle pump

You can't change the tire it is a soild rubber tire molded to the rim. To replace it you have to buy a new rear wheel. Here is a website that sells it.

http://electricscooterparts.com/razore100.html

Use a wedge. Place the thin end between the tire and rim. Then push the tire off using the wedge and your other hand, work your way around the circumference of the tire until it is off. Use the same process to put the new tire on. But this time you will push the tire on the rim.
This is a pic of the ideal tool you should use:

Click this link http://www.razor.com/support/pdf/manuals/current/e100-series-manual.pdf

Scroll down to chain and tire replacement. It has a full exploded diagram of the rear wheel

Hi
Deflate the tire and then you can gently move the valve to a straight up position. Now refill the tube.

Hi:
I have a rascal 3 wheel chair and the tire is flat on back, how do they come apart for repair, thanks.
Leroy