You can fly with the window craked or delaminated. If you have a look at 737 QRH, there is a checklist called "arcing, delaminated or cracked window". But the MEL, of course will not let you leave with the window not even delaminated...!
But yes, you can fly... Hoe long to replace? Never been trought that, and don`t know someone who has, so I really don`t know, but it`s a good question for an engineer!
Cheers