Algae can always be removed by scraping the sides of the tank with soft sponge. But before you do it, make sure the sponge is properly cleaned or else you run the risk of harmful chemicals accidentally introduced to your aquarium. As a good rule of thumb, one should never completely get rid of all the algae. Presence of some algae is beneficial because it will help to consume the nutrients present in the water and partly it helps to clean up the water.
Algae problem can be difficult if you have a tank with a lot of aquarium decoration. Algae growth among gravel bed can be very hard to wash and sometimes, one might need to dig up everything and wash in a bucket of clean water. Doing that will require a lot of time and I would not recommend because that makes a lot of mess. The best solution is either to introduce a bottom algae eater like the sucker fish or another approach is to dim out the aquarium lighting.
Both ways can be implemented but each has its own restrictions. For example, if you have goldfish, presence of algae eater can harm your pets because both fishes are not compatible. But if you have discus with sucker fish, then this is not a problem at all and your algae problem can be easily solved. Reducing aquarium lighting is not a good idea if you have live plants in your tank. Proper lighting is also needed to display your pet fish full color and with dim light, your tank will look dull.
Good aquarium maintenance practice like constantly changing new aquarium fresh water is also encouraged. Do not put more fish food than necessary and you should come up with a scheduled task list that you will need to follow and do your part on the cleaning. I believe a good algae solution is to tackle the root cause of the problem before it is too late. Prevention is definitely better than cure so it's up to you to create the best living environment for your tropical pets.