Well, actually I suppose the hardest part is to pronounce the other consonant hispanicized as -tl at the end (a soft lisp)
[ɬ] voiceless alveolar lateral fricative [0]
in a sufficient fluent manner (except you happen to speak e.g. Welsh, there the sound is written as ll so by happenstance the "axolotl" found in Wales can be pronounced fluently by the Welsh) otherwise you are saying it half correct which is arguably worse.
So let the nahuatl speaking people have a laugh at your expense for pronouncing it the germanic way or if you want to go unnoticed do it the evolved spanish romanic way, a good middle ground I guess.
Anyway I think it is generally a lot fun to hear words pronounced "wrong" by foreigners or having trouble hearing/pronouncing it "right" respectively heavy accents are hilarious icebreakers (:
[0]https://en.wikipedia.org/wiki/Voiceless_dental_and_alveolar_...
You're close.
The Welsh or Icelandic "ll" is not quite the same. That's a "voiceless lateral fricative", lacking the alveolar break that earned it the "t" in "tl" for the Latinized spelling. It's much closer than most languages get, but it is a different sound.
The Nahuatl consonant is a "voiceless alveolar lateral affricate". It is a single constant represented with [tɬ] or, more correctly, with a tie bar between those two glyphs: [t͡ɬ].