Unless this is a very subject-specific phrase, I think there may be a mistake. I've never come across the verb 'to guy out', and can't find it in a dictionary. Was it supposed to say 'gut out' perhaps? If this were the case, the sentence would mean that you had to get rid of all the data you had entered into the database during the day, and then re-enter it all. Another note: completely not completly.
NB: this strikes me as a very rare use for 'to gut out'. It's more often used with animals or fires:
"He gutted the chicken out" i.e. he took the guts out of the chicken.
"The fire completely gutted the house" i.e. the fire destroyed everything in the house.
Definitely double check the sentence though - I may be wrong.