Yes you can change your DVDRW to a BR- Drive. But note that your GPU must be fast enough to render 1080p video. You can try ordering it from
PCandParts.com.
Concerning blowing dust, you can buy a can of compressed air sold at some libraries like Malik's Bookshop. You can also buy a leaf blower if you blow dust very often.
<Speaking of leaf blowers , anybody know where I can buy a small cheap one ? >
Also remember to blow the dust from the bottom and from the side of the laptop by shaking the air being blown in. Because sometimes dust bunnies get stuck in the heat sink. Be careful not to get the dust stuck inside the fan, or else it won't turn and you have to take it apart.
Most importantly don't forget to blow air every few weeks, because laptops can collect a lot of dust in a few weeks or a month or two.
Good luck :)