The easiest way to exchange the torn bills (if the damage is not too strong) to pay it in the bus or in a taxi. The drivers at the end of the day pass revenue to the General Fund, so to accept payment in virtually any currency. With the exception of banknotes of which are missing any parts, so if the bill is torn into several pieces, please glue them together with tape.
To pay off a torn bill, you can market or grocery tents. Typically, the sellers are retail outlets that do not have cash registers, without objection to accept corrupt money.
If the damage bill is so great that does not allow her to exchange the above methods, (e.g., banknotes torn off a big piece or is it broken into several parts), you can pass a bill in one of the branches of Sberbank of Russia.
To convert you need to contact the Bank with all the torn banknote and identity document (passport). The bill will be adopted by the Bank employee even if it is glued together from two halves of different bills having a single denomination.