No need to get grumpy, if there was a member who read this and could help then they would of replied. But alot of people only read threads that grab their attention and unfortunatly the telstar isnt the most appealing subject to read.
But of the tens of thousands of members on here alot of them have probably never had to replace a window and those that have had to replace them usually pay a proffesional to do it for them.
It makes sence to because to tools they use to remove and replace a window correctly and proffesionally are usually worth more then fitting the window itself.
Try contacting a few window replacement mobs and explain your situation, some would rather do the job and get payed off in installments than not get the job at all. If your lucky one of them will have an easydebit system where you agree on paying a certain amount at intervaks that suit both parties.
We do this at work where a customer has an unexpected breakdown and cannot afford the job straight up. We do it, they fill out some paper work and the job gets payed off over time.
Or you could just google it or search youtube
Good luck with it