Got a 90 rmx250 how do i change the spark plug?

Question

also does anyone know exactly the amount im suppose to mix oil in a 5 gallon gas tank

Answer 1

Remove the old spark plug, on the top of the cylinder head, with a spark plug wrench and install the new one?

I don't understand what's confusing you.

Purchase a service manual -

http://www.motocom.com/motorcycles/

Mix the gas and oil at a 32:1 ratio.

That's 4 ounces of oil to every gallon of gas.

Answer 2

Sorry, mix oil in a gas tank? You do that? I would'nt know, heh, I really can't help you, but... yeah... A simple motorcycle repair/maintenance manual would be your answer. A bit of googling might turn one up on the internet.