Guaranteeing fifth place with victory at San Siro would cap a remarkable season for Guidolin's Bianconeri, who until March looked set to miss out on European competition for the first time since 2010.
A recent run of seven consecutive wins has given Udinese the initiative in the race for the Europa League because, if Lazio fail to beat Cagliari tomorrow, they must see off city rivals Roma in next week's Coppa Italia final.
Guidolin told La Repubblica: "We are going to Milan to win our own Scudetto.
"We face the challenge of an incredibly capable side, one rich with quality, but like always we go out there to do our best.
"There is no margin for error and tomorrow's match will be difficult for a number of reasons.
"We won the reverse fixture 3-0 and a whole round of games has gone by since in which we've improved and become much more cohesive.
"I'm tired just like everybody else but this is the last leg and we can't afford ourselves the luxury of feeling tired."
Guidolin confirmed talismanic striker Antonio Di Natale - scorer of 25 goals this term - will start in Milan despite hobbling off injured against Atalanta last time out.
"He hasn't managed to train regularly during the week," the Bianconeri boss added. "But he will take his place tomorrow to hopefully give us a push over the final obstacle."
Midfielder Andrea Lazzari is Guidolin's only confirmed absentee while Inter counterpart Andrea Stramaccioni drags an injury-stricken squad over the line.
Defenders Andrea Ranocchia, Cristian Chivu and Javier Zanetti, midfielders Joel Obi, Gabi Mudingayi, Walter Gargano and Dejan Stankovic join strikers Antonio Cassano and Diego Milito on a high-profile list of absentees.
Stramaccioni takes control of the Nerazzurri on the last day of the season thanks to the backing he has received from president Massimo Moratti, whose understanding of the serious personnel crisis has prevented him from dismissing the young tactician.
Today saw the top men at both Napoli and AC Milan admit there were career decisions to reveal at the final whistle tomorrow night, but Stramaccioni would not take the bait from assembled reporters.
He told inter.it: "I'm smiling because I don't think you like my answers. Both the president and I have provided clear answers on this matter for a long time.
"I don't want to be the one who bucks the trend, (Walter) Mazzarri will speak after his game, (Massimiliano) Allegri will speak after their game, so why do I have to speak now?
"I'll let my president do the talking. I will be Inter coach tomorrow and I'm sure that if there's anything interesting to be said after the game it will come from the president's mouth.
"The boys and I are fully focused on tomorrow."