A 1500 cal jump is a bit much to do at once.

I'd say do it in 250-500 cal jumps per week.

Since you're already eating at 3000 cals, doing the 500 cal jumps shouldn't be too bad. So that would be, 3500/day for a week, then 4000/day for a week, then up to the 4500.

The 'safer' side (to prevent fat gain too quickly) would be in the 250 cal addition on a weekly basis. That would be one week of 3250, one week of 3500, one week of 3750.. etc. til you hit 4500.

Up cals to a certain degree, see how you feel on that jump, then go from there.