Can you change your Facebook Profiles?

Hi Guys,

Great site & my first post.

I currently have a "fan/business page" in the pet niche.
A problem I am finding is when I join a group, my profile name shows up which is totally unrelated to my niche.
I thought I could simply sign up to a group using my fan page but the message came back saying "Admin as agreed to you joining" but when I tried posting a picture it was from my Profile name.
I can imagine the group's admin saying "Er, who is this guy"

Is there any way round this?
Can I change my profile name to match my fan page?
You will see an option to post as a page if you use the desktop version

Google it for tutorials
Agreed, I can post as a fanpage, but this is about joining other groups. When you ask to join a group through your fan page, you can only join as your profile, which shows your real name. So now, you can post to the group but everytime you do, your real profile name shows up, not your business page name.
Does anyone agree with my experience or have I got things mixed up in my privacy or admin settings?