Speech for a colleague leaving

Hi all,

I'm desperate to get some advice! I need to held a speech for a colleague of mine whp's leaving the company after 25 years to pursue another opportunity outside the company.

Now, after working 7 year very close with that person, I'd like to held a speech which should have an ironic taste. I know the guy very well but what I need is some guidance.

Any advice is very much appreciated!

Thanks,
/mick