When we want to add more weight to a lure, normally we put weighted sheet on belly of the lure.

It is good as easy way.

But, in case of real finish lures such as big swim baits, it is not so good idea because of not good looking for Bass.

In case of Gillroid, you can add weighted sheet to the jointed part.

 

 
You can put some of weighted sheets there.

How to make separate,

Remove the screw off with care, that is all.

 

 
Depending on the circumstances, the weights to be added shall be adjusted.