How to find the three missing pokemon (especially Steelix) inpokemonlight platinum

In pokemon light platinum, there was a stage where I got stuck and so I couldn't find 1 of the three missing pokemons (stelix) so I tried to look it up to find the answer on google and well, I couldn't find an answer, there was no walkthrough of any sort, so what I did was, I kept on looking and looking and searched the whole map, it took me hours and well i finally found it. 

So for those who are stuck at this stage, I am posting a blog in which Im giving clear steps so that those who are stuck, well, wouldn't be stuck anymore.

I tried to keep the steps as straight as possible so that those people who play pokemon light platinum and are stuck at this stage would be able to find it (the third missing pokemon) easily. As a bonus I've put the method of finding all three pokemon which includes (a Shinx, a Snorlax and a Steelix).

So without further ado, let's get to "how to find the three missing pokemon 'especially Steelix' in pokemon light Platinum"

In Ricyan city
in the Lauren Region you'll be given a task of finding three pokemons which just escaped from the zoo.

The pokemon includes a Shinx, snorlax and a steelix
You'll need to talk to Soka (the gym leader)

She will then ask you for a favor 

Shinx is in the route 509

You'll find snorlax in the route 508 near the Merydian city

And now for steelix

You need to go over the sunsun lake

From this point

To this

And finally you found steelix 

I hope this helped. Also check out my other posts.

Thanks