Battery Back-up Unit - Intermittent Beeping - Battery may need replacement

[CDJ2]

I've looked through the forums and found the solution , however I cannot open my BBU to remove the battery.  I called Verizon for help they said I needed to slide it open and then openit.  I tried to pry it open with a screwdriver and a knife.  Is there a diagram someplace where I can see how to open this thing up?  Or better yet can I just unplug it?  If the BBU is only needed to supply power to my landline in the event of a power outage its useless anyway since all of my phones are cordless.

Thanks in advance for your help 

[jonjones1]

https://www.verizon.com/support/consumer/battery-backup#navbar

This has step by step instructions.