Forwarding Workflow for approval

Hello Experts,

A 'Maintain Position' workflow was generated by an employee. Ideally it should have gone to the employee's manager as first approver, but since the manager is not set up in SAP, the workflow has gone into error (its shows in Tcode SWI2_DIAG). I need to forward this workflow to another manager for approval as it's urgent.

I guess using SWIA might help but as I am new to workflows, I am not sure of the exact steps to be followed. Can someone please help me out on this?