Transaction Variant ??? Modifying????

Hi Experts,

By using SHD0 tx,I created a transaction veriant- my_fv50 for SAP's FV50 (in which I deactivated the POST button in INITIAL SCREEN).

By SE93, I created a tcode as my_fv50 of type Variant Tx with follwoing values/entries,

Tx- FV50

Tx varinat - my_fv50.

Working fine, after setting the authorsation at basis/security level.

Now, I need to MODIFY/add extra feature to this existing my_fv50 Tx Variant!!

xtra feature, am looking: fv50-- ->Initial screen ->specify values-- >SIMULATE button ->here we can see the again POST button --->here I need to deactivate the POST button!!!!!!

pls. clarify that How to change/modify the existing Z transaction varinats?

thanq