Reply to legal notice

Yes it is valid but without the advice of lawyer and due to lack of knowledge of law and it's consequences it may damage you.

Knowing law and practice is a prolonged business which can be done by a hardworking advocate only. Nothing wrong in sending by yourselves but, it may not be worthy considering the points to be raised in the reply

One can give  notice without engaging any advocate but he should be very cautious of using the words in the notice because every words mentioned in the notice has an implication. It is advisable to be very precise and to the point when writing a notice. Avoid unnecessary details.