For Put ratio spread,

1. Take off long Put Vertical Spread when net credit is close to width of the spread.
2. Left with short Put. Roll out in time when 21 DTE.
3. Sell Call to turn it into strangle/straddle. No change in BPR as there is already short Put opened.

See video here

Step 1: Cover The Spread

When the debit spread portion of the trade can be closed for near max profit, the debit spread portion can be sold while holding the additional short option. 

Step 2: Roll Out The Extra Short

If the trader wants to extend duration on the position, the short option can be rolled to the next month.

Step 3: Sell Opposing Option Against it

Becomes a strangle

Full video here