Change Digital Signature Flow in SAP Solution Manager 7.1

Hi Experts,

We have digital signature configured in our SAP Solution Manager 7.1.

Currently for a document type A, we have a 4 level signature flow: Sign1-> Sign2-> Sign3-> Sign4.

I want to change this and remove the third one from between, and make it to Sign1-> Sign2-> Sign4.

I have not used this digital signatures before, and therefore it is new to me.

Can someone please let me know where exactly we do this?

Thanks.