Adding an ASDR to an existing patch

Completely fell in love with this patch

I really want to modify it so it has 4 controls for ASDR. (Atm it has one decay knob which seems to be control the decay and release). Can anyone point me in a direction on how to do this? Had a look at some tutorials on making basic synths using pure data and this has helped me to figure out how to programme envelope generators. But im still pretty clueless. Anything in particular I should read before I have a stab at this? Is it way too much of a task for someone who doesn’t know pd at all?