During my university years, I had designed and developed my department website. It's been many years since I graduated, however, the office IT staff still contacts me if something goes wrong. This happens because the website was made using a web framework whose expertise is rare, and which is now getting outdated. Anyways, I respond to all their queries, as I feel a sense of belonging to the department.
However, time is more precious now and I want to stop this "free" continued support. I want to update/migrate the website so that it runs without issues for years. This will take about 2-3 weeks of dedicated time, which will require me taking off from my job. So, I would like the department to pay me some token amount so that I do not feel guilty for investing my time.
I want to communicate the same to the Chairman. However, he knows me well as a student and we hold a good student-mentor relationship. How should I ask him without making the offer appearing cheap? Or, should I drop the idea altogether and simply tell them to take someone's service professionally? Note that I personally want to refurbish the website myself as it has carried my name for years and I wish that it continue to do so.