my heater core just went out on my 88 4runner i was wondering if it is hard to change and if anyone has any helpful tips

There is only 1 special tool you need and that's a special pressure line disconnector tool (also used for air conditioning lines). It's essentially a set of plastic rings that slip over the line and you pull into the connection to release the teeth.

The rest of the job is getting all around your dash and pulling it away from the firewall so you can get at the heater core.

It's not hard, just time consuming. Suggest you buy a Haynes manual at Wal-Mart because they are very good and will delineate how your dash comes apart.

Even with this manual, I had some screws left over that I never did find out where they fit. Oh well, the dash never rattled and all worked fine.

Go for it.