Hi Guys,
Just want to contribute to this thread - i've always been in the frame of mind of leeching of others (self gain) and not contribute to the community as a whole.
I want to thank baysidebluebnr34 for the valuable information you put above. Your method does work with the added modification of inserting a sleeve on the cut sections of the aluminium pipe coming from the firewall to the matrix. I've taken a step further - i managed to release the matrix from the two aluminium pipes using a screwdriver to gently massage the pressed tabs open as it connects to the matrix. The key is to take it slowly - alot of people suggested that once you mess with aluminium (especially if it's been in the car for a while) it may fracture. As mentioned, key is to take it slowly.
Once both pipes are free (and with the instructions by baysidebluebnr34 then you'll be able to remove the matrix leaving the pipes intact. My matrix was blocked due to lack of coolant change thus causing rust and debris to build up in the matrix. Also, my thermostat failed at one point (i thought it was my water pump - phew!).. which caused some of the rubber gasket to perish and get lodged in my heater matrix.
After removing the matrix i decided to replace it with one that was pulled from a lexus of 1 year of age (lucky me!)..
When i came to re-install - i did everything in reverse however i added some RTV gasket sealant (made for replacing gaskets in around lubricants like oil / water etc). This stuff, once set doesn't shrink and can take temperatures below -62C to 370C - i'm sure my temp wont hit the bottom or top of the said tolerance. after reconnecting the pipes i added some more of the RTV sealant just to be sure. My car's heater is like a hair dryer now - toasty! With the thermostat replaced the heating on my car works efficiently and brings the heater in action within a few minutes.
I have taken pictures which i shall upload shortly.
I hope this post helps others - i may make a video as i know there isn't one available but will help the mass.
Any questions - please fire away.