Modifying Master Pages on Personal Sites ( My Content)

Hi Everyone,

I have branded MySite and Personal site collections using the branding code but I am running into an issue.

We are trying to give a uniform look to all the users when their personal site collections are newly created.

Once the master page are under the personal site collections , how do I change the master pages programmatically ?

I have written code which switches the master page to default master page ,deletes the current custom master page and activates the feature which deploys my custom branding .

I am running into "Access Denied" error in my code when I try to execute the above code for personal  ( My Content)  sites of users.

Any solution or hint will be much appreciated.

Thanks,

Shilpa