For the love of god, don't do it.
Even if you know what you're doing, don't do it.
Assuming you disregard that or get one anyway, read this:
http://www.axolotl.org/tiger_salamander.htm
this:
http://www.pnas.org/cgi/reprint/94/25/14185.pdf
this:
http://salamander.uky.edu/srvoss/pubs/1.pdf
and revisit the forum on
http://www.caudata.org/forum and ask questions about morphing, and their care.
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Morphing is achieved by thyroxine injections. Most specimens die, either because generally speaking, forced evolution usually doesn't have positive results and/or they cannot cope with losing about 75% of their body mass through the metamorphosis.
If the procedure is done incorrectly, specimens will also need ongoing injections to help maintain the condition of their skin (when an axolotl becomes a morph its skin becomes akin to a frog's).
Unless cared for by an experienced Caudate keeper, specimens usually live a depressed life, barely showing any desire to eat. No recorded morph specimens have ever mated, but even if they did, they would just lay axolotl eggs.
Pulling an axolotl out of the water is cruel - go pull a fish out of the water and see what happens. Forcing an axolotl to use its rudimentary lungs any longer than necessary (they take a gulp of air from the surface of their tank every now and again as you know) is cruel.
gradually lowering the water level generally won't work either. Iodine and Water level lowering are used in conjunction with the thyroxine injections to achieve the desired result - and the success rate is very minimal indeed.