You can check your RAM type by software in your operating system or manually by opening RAM slot on the back side of your laptop and then proceed to replace RAM boards with same type but stronger editions.
Most of laptops usually are manufactured with two or more RAM slots where you can plug the extra RAM module of whatever capacity or if it has one RAM slot you can remove and replace it with a higher capacity RAM.
You can increase your RAM by adding other RAM to your laptop. Most of the laptop usually have an extra slot where you can extra RAM module . If you don't have extra slot then you can remove the existing an put the with higher RAM capacity.
remove the existing RAM and replace it with a higher-capacity RAM. For example, if you own a laptop with 8GB of RAM with a single RAM slot, in such case you may have to remove your existing 8GB RAM module and replace it with something higher.