how can I add a tolerance to a switch(sw_tclose) part

I can use cbreak for example, to add a DEV=5% to its cap value.

but how can I add a tolerance to a switch(sw_tclose) part, there is not a  tclose part in the breakout library.

I want the switch close at time 100ns+-10ns for example, how to do it?

I right click on the sw_tclose part, and chose "edit pspice model" , try to modify it , but not right?

how to do it ?thank you