How to disable or grey out fields on CHARM_CREATE or CRMD_ORDER screen

Hi Experts,

In order to create Change request for CHaRM can enter tcode CHARM_CREATE or CRMD_ORDER ( click on create change request).

In the initial screen, need to disable or grey out or remove the following fields,

Change Advisory Board,

Product ID,

Ext. Reference#,

Reference Date

Also in the same screen How to set default value for following fields:

Sold-to Party, I

Base Component (based on logon user or if need to hard code ),

Category to Various,

subject to Correction