avr How to redesign a circuit to use a current sinking IC rather than a current sourcing IC

Building a serial servo controller to learn about electronics and assembly language as part of my hexapod robot project. Quite early on I decided that I needed more I/O channels than my ATTiny2313 that I was using at the time supported so I investigated some 3-8 line demultiplexer chips ( CD74HCT238E `s) which have allowed me to create a 64 channel PWM servo controller with just 8 I/O pins for the PWM channels and 3 address

lines. Anyway. I also bought some CD74HCT138E `s which are active low rather than the active high CD74HCT238E`s. I understand, in principal, the differences between the current sourcing chip that I`m using and the current sinking chips but I don`t really know how to adjust my circuit to use the current sinking chips instead of the current sourcing chips. Note that the reason for asking this question is that I bought a tube of the active low ICs by mistake and I`m curious at how much more complex the schematic and circuit design would need to be for me to make use of them.

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