I have to buy Lenovo H530 57327877 desktop but i have little problem?

I want to buy a new desktop and i choose:
http://www.newegg.com/...6883266535
but my problem is the PSU the PSU of this PC is 280W and i can, t upgrade the GPU to GTX 760 or any else high end GPU, s.
can i replace the PSU of this desktop?
on Dell Optiplex PC, s we can, t change the PSU becouse it have his own PSU and it is not Replaceable but i don, know about Lenovo H530 57327877
i need little help about this case

Added (1). i need a 600W compatible PSU

Guest

I haven't yet met a desktop case where the PSU could not be be replaced. You can replace the psu on the Dell optiplex (see example on ebay), but maybe not upgrade it.

David

But it is only around 305W or 400W i need 600W PSU for this lenovo Desktop

Muzamil