Can a network guy move a phone system to another T-1 line?

We are switching our phone provider from Integra to C-Beyond.

I don't have much experience with phone systems, as I'm I network guy. I guess I'd like to attempt to handle this change if I can rather than paying our local phone provider $200/hr for after hours rates.

Here is a picture of the equipment in the phone closet: <A Href="http://www.oneadamclaude.com/PhoneSystemPic.jpg">http://www.oneadamclaude.com/PhoneSystemPic.jpg</A>

There is a cable that comes out of the Adtran (highlighed in Cyan) that is a 25 pair connector that plugs into the 66 block. All of our phone numbers are marked in pen on this 66 block.

What is the name of this 25 pair cable (it looks like an old school SCSI cable)?

When C-Beyond installs their equipment, how does it interface with the existing phone system? Will they provide another 66 block that I will move the existing wires (Red) into the new 66 block? Or, will it have another 25 Pair cable that I just unplug from Integra's Adtran and plug it into C-Beyond's equipment?

Also, and unrelated question: The blue arrow points to a jack. Is that the demarc? When the phone guys talk about "extending the demarc" does that just mean running the blue cable to this jack in the customer's office?

Is there anything else I should know to complete this task?

Thanks in advance!
PhoneSystemPic.jpg