How do I clean the laptop from inside?

that would be very hard to do unless you were an ant or spider.........

..................

The only thing you can do is to BLOW it out with compressed air.

Start by blowing into exhaust fans. then blow into air ports.

If there are multiple ports, cover others.

BTW - it most likely isn't a lack of air that is slowing it down, unless it is really blocked up - which it probably is not.

If it were, your fans would be driving you out of the room being very loud.

You need to clean up the system -- hard drive, background running programs, browser caches, etc.

When it runs slow would be a clue to what is slowing it down.

Boot time = hard drive errors, corrupt system files, or slow hard drive

internet use = browser cache, browser addons, too many tabs open

High resource usage like games or CAD programs, etc. = not enough RAM

This process should be done periodically:

Start by opening a command prompt as administrator:

enter CHKDSK C: /F - look up operation if you need to

If you have multiple drives or partitions, run it on all of them (change the drive letter)

Then enter SFC /scannow

You may also need to run dism /online /cleanup-image /restorehealth

If you only have 4GB RAM, you can likely upgrade to 8GB. Check you laptop manual.

Clean up your browser cache. and addons.

AV programs can also slow it down.