I have a simple SOP,

1. MA20 cross above MA10 Open Buy (vice versa for SELL)
2. If hit TP, close and start again.
3. If not hit and market reverse, open 2nd order with double lot (and clear TP for first order)
4. This will continue until Max Order-n.

I can do step1 and 2, but not sure how to do on step 3 and 4 (especially to add to volume on the lot and modify the SL for previous order.