Your Vauxhall Astra 1.6 2003 has INSP lit on speedomoter how do you remove this?

Have a look in the handbook. The information is contained within.

This should appead for only a few seconds in the "Trip Metre" when you first turn on this ignition if I am correct.

This is just your car's internal computer telling you it hasn't been reset in a service by a Vauxhall dealer.

You can take it in to one to have it serviced or just deal with it