Loosen the right side wheel central bolt with the respective spanner by rotating in anti-clockwise direction.
Loosen left side wheel central bolt with the help of respective spanner by rotating in anti-clockwise direction.
Once both the central bolt are loosed, its time to loosen the chain by loosing small adjustment nuts with the help of spanner (size 8-10 and rotate the spanner in anti-clockwise direction) Once the nut is loose, rotate the tire and check for equal play at all the place.
If you feel chain is tight some where or its loose at some place, either loosen or tighten the adjustment nut respectively.
Once you get an equal play at all the side of chain, start tightening adjustment nut by slowly rotating in clockwise direction and keep chaining chain position in between while tightening just by rotating wheel.
(Note - The rule of thumb is about 1 to 1.5 inches of slack)
Also tighten the chain adjustment nut on the right side.
(Note -The rule of thumb is about 1 to 1.5 inches of slack)
Tighten both the side adjustment nuts till you read the same scale on both the side. (different grove or line indication will be there on the scale)
Now tighten the central rear wheel bolt from the both the side. If require measure the play (Note -The rule of thumb is about 1 to 1.5 inches of slack) and take test drive of your bike to check the difference.
Chain adjustment require different tool at the same time person should pay an extra attention. Hence if in case of any query or problem or difficulty or any bike service, please contact Doers mechanics to resolve the issue.