twist and lock

[Billhart]

If this is the kind that I think that it is they are a twist and lock connection.

You turn the bulb counter clockwise and then pull it out.

http://www.servicelighting.com/catalog_product.cfm?prod=QQ64705

Note there are two types of these. Ones that use a GU10 base and operate off 120.

And ones with a GU7 base and work off of 12 volts.

the GU7 ones are very rare. I had more than one lighting store tell me that there where no such thing untill they went to their catalog.