Assuming that you are just renewing an expiring passport and the proceedures haven't changed in the past 9 months since I did mine, you shouldn't have to get the counter signatures.
From the High Commission website :-
"Countersignature of the form and photographs is not necessary for those people over 16 renewing a passport, unless your appearance has changed significantly since your previous passport was issued."
In any event, you take the completed application form to any Postshop and they will check it over for you before couriering it to the High Commission.
Mine came back in about 3 weeks, surprisingly quick really
Hope this helps