Given below is an example of how CW min of a wifi node can be changed

1. Create a simple scenario with 1 AP and 2 wireless nodes

2. Run simulation for 10s

3. Open temp path of NetSim (C:\Users\tetcos\AppData\Local\Temp\NetSim). Right click on configuration.netsim file, select properties, then uncheck Read-only and click on Apply and then ok

4. Open configuration.netsim file

5. Change the cw_Min value of any device (for example node 2) as per the screenshot below and run simulation in CLI mode (refer section Running simulation via CLI mode from NetSim's user manual)

DIFS value of a particular wifi node can be changed by following the steps below

1. Open NetSim solution file

2. Go to IEEE802.11 project and open IEEE802_11_Phy.c file

3. Modify the fn_NetSim_IEEE802_11_PHY_Init(NETSIM_ID nDeviceId,NETSIM_ID nInterfaceId) function to change the DIFS value of a wifi node 2 as per the screenshot below 

4. Rebuild the DLL and run the simulation