Urgent Advice regarding 10 Years Long Residence

[aakkoo]

Do i have to send the change of circumstances form if i want to vary the Tier 1 application to Set(LR)?????

I already sent the sent my SET(LR) without change of circumstances form, now little bit worried .

[aakkoo]

I varied my application from tier 1 to Set(LR). My dependent (Wife) application is with my case.
Yesterday i got a letter from UKBA regarding my wife FLR (M) application. Asking me which application i would like to proceed. I want to know should i reply via post or email as in the letter there is an email address of the case worker as well.

Plus wanting to know if replied by post where do we post the reply. To the address on the application form(Durham) or to the address on the letter(Sheffield).