Heating core replacement chevy van

i am trying to replace the heating core of my 95 chevy 5.7liter g20 cargo van. it leaks fluid inside the car in front of the passenger seat. i bought a fix-it manual from advance auto parts for instructions, but they don’t really make any sense. i don’t know what the words mean. there is only one accompanying picture, so i don’t know what other parts, bolts, hoses, screws they are talking about. for added irony, the picture shows the heating core case, which is readily identifiable, with arrows pointing to the obvious screws. i’ve searched online for others giving advice on this, but all the instructions are not very specific on details such as about which hose to pull out. is there anyone who has done this before?

I have not done your car but the typical set up is 2 hose connections at the firewall (engine side of floorboard) going to the heater core, that way warm fluid enters and exits the heater core to provide heat. The hoses probably disconnect on the engine side of the firewall. Then you are under the dash to access the heater core inside the heater core case. You would then open the case to reveal the heater core, remove and replace then connect the hoses on the other side of the firewall, please ask more questions if you need!