ABS senor

Hi, ive searched but didnt find exactly what i needed.
i have a 300tdi es '94, having no end of problems with the ABS and its constantly saying there is too larger air gap in front offside sensor, i adjust. no difference, there is very slight play in the wheel bearings but not what i would call excessive.
how easy is it to get the front sensor out to clean it? does it just pull out? what should i be especially careful of?

desperatly need this to work as i just got it back from the garage with a 600quid bill and it only worked for a day.

its easy to get out just give the area a good clean before you take it out so you don't get any dirt down the hole, clean it all up and pop it back in give it a few light taps to seat it and thats about it, if that don't work i would get rid of the slack in the wheel bearing and then tap it in again.

worked for mine