dell studio 1558 dust cleaning

hi, i would like to ask about is there a way to reach to the fan so i can clean the dust without completely torn my laptop apart? did some browsing on internet that's the only way to reach to the fan but i'm afraid doing so would break some of the components by accident.

my laptop has recently slowing down and heating up badly, even on normal web browsing it could go up to 70 celsius for the CPU and 50 celsiu for the GPU. and i already using a cooling pad so it might be worst if i don't use my laptop on top of my cooling pad. so this is why i want to know about a method to remove the dusts from the laptop. also thought of forcefully making a hole under the fan so i can reach it without torning my laptop apart but not sure what would happen and will i be able to really reach the dust.

please any experts here give me some guidance or advice