removal of left hand crank

[princeperch]

this will no doubt come across as a really stupid question.

however, I have a jamis beatnik. I need to remove the left hand crank and replace it. I have a replacement. I have removed the centre screw thing from the middle of the existing crank. however, I presume that it is the little silver circular plate thing (with indentations on it) that is keeping the crank on the bike.

can someone please direct me to the correct tool on the internet to loosen this silver disc thing so I can remove the crank?

ta v much.

[GaryGlitter]

If it's the model in this linky then you'll need a crank removal tool.

Proper one

3.14key one

[matt-ITR]

Looks like an internal BB - in which case you need a crank remover as linked above.