How To Repair Cracked Bluestone Step

I am a complete newbie when it comes to cement/mortar work but I am used to doing alot of DIY around my house. I have a flagstone walkway and stone steps laid on top of brick that go up to my front door. the ii stone steps take gotten very loose and one has completely bankrupt loose. I removed it and placed information technology on the floor then that information technology doesn't fall and cleft. I've seen several youtube videos on how this repair can be done. I've seen people suggesting that landscaping adhesive would be enough, but I suspect that is not the "correct" way to practise it. I've also seen the quickrete quick repair kit used.

Simply I call back the right fashion is to lay down mortar, level it out and and so place the stones on top of them. The stone on the left is as well loose so I will probably remove that every bit well and re-do both at the aforementioned time to make leveling a little bit easier. I am also overwhelmed and dislocated well-nigh what product to buy. At that place are so many permutations of concrete mix and mortar at the store that I take no idea what i need in my application. I currently purchased two 60 lb numberless of quickrete mortar. But the guy at lowes told me to use portland cement, others say to use the quick repair, etc. What is correct to use in my case?

Can i just clean up whatever loose cement/mortar that'southward there, lay mortar on top of the existing surface and identify the stone back on tiptop? Or do I have to chisel away everything? I would like to do this chore correctly then I can larn a affair or 2 as well. Is this likewise a job that may be better off paying someone to do? I have a feeling that I would be charged upwards $500+ from a professional to do this work. I had asked someone to repair some slap-up joints on my walkway and got some crazy quotes.

https://imgur.com/a/hQDyMl6