Integrated chipsets are not replaceable. If your motherboard supports adding a graphics card then you could add a support graphics card, if it doesn't then you will not be able to play the game. It's as simple as that.
It may be possible to upgrade the Intel driver (for Intel chipsets) to improve support and get the game running, but software pixel shaders are slow and the game may run very slowly as it makes heavy use of pixel shaders.
My current laptop has the ATI R200 IGP integrated graphics (
http://en.wikipedia.org/wiki/Radeon_R200) which claims to support PS 1.4, and this also cannot run Buccaneer. There is no pixel shader 2 (the minimum requirement for the game) upgrade for this chipset, so I have no way to run the game on here - but I use the laptop just for net access from my living room so it's no big problem for me, I just play on my desktop PC.
The bottom line is that trying to run games that make heavy use of 3D hardware features on a basic integrated graphics chipset is almost always going to result in either the game not being to run, or running so slowly as to be unplayable. They are designed for use on laptops and budget PCs that are not intended for playing sophisticated games on.