Does anyone have the refill procedure ? I check the service manual and it suggest using a special tool with compressed air. Seems a bit much for just a simple drain and refill

That special tool that they refer to puts the cooling system under a vacuum. When the system is under about 28 to 29 inhg vacuum, the coolant is then added, filling the voids produced by the vacuum not leaving any trapped air in the heads or heater core. I wish I could tell you a easy way to do it, but I've never done it without the coolant fill tool. Someone on here is bound to have changed it without one before.

The old way of doing it is to drain, fill, add a little extra to the resevoir for settlement, then check again in a couple days after it settles. I'd assume this tool just prevents from having to check on it again later.

Search for "radiator flushing" (thread number 35998) at www.titantalk.com, they list a procedure there on how to flush and remove the airlocks without the tool. You need to do this or your heat may not work right or at all..

Here it is, this worked for me or you can use the tool which is about $100 bucks.

http://www.titantalk.com/forums/titan-general-discussion/35998-radiator-flushing.html

In addition to the tips listed in the titantalk link. When re-filling the radiator, to prevent from building an air pocket in the engine, remove a coolant line or fitting at the highest point of the engine. During filling, when the new coolant has reached that highest point that you've opened up, you will have removed just about all the air from the engine that otherwise would have been trapped. (air pockets are a bugger-bear to get rid of)
As for disposal of old coolant, check with your City Waste Management department. My guess is they'll tell it's okay to flush down the toilet. The millions of gallons of water in the sewer system will dilute the coolant to absolutely nothing. Plus, this water is directed to a water treatment plant. In Houston, this method of disposal is posted on the City's website. Do not pour down the rain gutters, as those feed directly into lakes/rivers and ultimately the ocean.