So I got the answer for you, no pictures this time, just follow the link to see the Dell Inspiron 15 (1545) Motherboard System Board with Discrete ATI Radeon 4330 Video - H314N - yes, it is soldiered to motherboard and NOT REMOVABLE!! http://www.parts-people.com/index.php?action=item&id=6183
Compare the pictures, the one I provided previously is missing third heatsink inline with processor - your Discrete video card.
If parts are still available it cost $200, plus you will need to change $$ heatsink, do a lot of work and may be spend more $$ - you would have to change motherboard yourself!
So, if you want to invest $300-400 into old laptop go ahead, or just buy a new one and check what you are buying, so you would not look for the "upgrades" after.
There is nothing more to say here. This is the BEST answer to this situation I seen on many boards including Dell Laptop Community forum.