How do I enter Ytd Data if I return to Sage 50 payroll?

I was previously using Sage 50 payroll and had it set up.  I used ADP for a while and am considering returning to Sage.  However, my Holiday pay owing amounts and YTD amounts for payroll all will need to be reentered but I closed historical mode years ago.  How would I be able to enter the starting numbers I would need to start using it again?  Is there a way to reactive the historical mode or otherwise enter opening balances?