Water is leaking into the passagers floor board
how do I change the AC cabin fillter on 1993 Chrysler Town & Country
It is very likely that your van is not equipped with a cabin air filter.
A 1993 T&C doesn't have a cabin air filter. The water leak is most likely that the evaporator drain is clogged. Find the drain tube usually uder the hood on the passenger side of the firewall. It will be a black tube running straight down towards the ground. Using something like a weed-eater string slowly push into the tube to dislodge and debris such as leaves and things. If this doesn't get the water flowing you may have to remove the whole evaporator box ( big pain) and clean it out.