How to unlock a laptop without password

Bring it to Bestbuy , the geeks can help you do that for $$$ 

https://duckduckgo.com/?q=unlock+laptop+no+password&t=h_&ia=web

That search showed many ways.

Or just boot off a Linux disk / USB stick.

What approach you take probably depends upon whether or not you want to keep the files and installed software on the machine,  or just want the machine with a new, clean OS.

Not knowing if you have a Mac or PC (Win-xx OS) I would say look up your particular model and operating system, then adjust your search terms to that OS.

Then you can probably reset the PW in an hour or so of effort.
Or just pop a Linux CD / DVD in the optical drive and run that;  it's probably going to let you see the directories and files on the hard drive. From there you can figure out all sorts of stuff, or at least transfer files to your USB stick.

Ubuntu or Linux Mint DVD's can be purchased with a colorful computer geek magazine at your local Magazine shoppe,  or you can download those for free and make a bootable disc or USB stick.

Umm don't ever bring your computer to Best Buy

Geek Squad computer repairmen have reportedly been working with the FBI for at least a decade, according to documents acquired by the Electronic Frontier Foundation. The FBI paid Geek Squad employees to flag and disclose illegal content found on the computers they repaired,

https://www.eff.org/deeplinks/2018/03/geek-squads-relationship-fbi-cozie...

Umm don't ever bring your computer to Best Buy

Geek Squad computer repairmen have reportedly been working with the FBI for at least a decade, according to documents acquired by the Electronic Frontier Foundation. The FBI paid Geek Squad employees to flag and disclose illegal content found on the computers they repaired,

If any person(s) repairing and/or reviewing a computer and it's files finds child pornography (like in the above link) they have to report it or they are just as guilty as the person who put it there in the first place. As a former network administrator/director every company I worked for had that spelled out in workplace rules. Smart business policy for all involved. 

Not worried about that, Just having someone digging into his personal files is an intrusion that should be illegal!

With the odd exception, the last thing any computer repair person wants to do is dig through personal files. The problem is that the job given to them sometimes dictates that they have to take a look. The quicker a computer is repaired/files recovered, the quicker the job is done and one gets paid.  

I don't suggest any online methods. How to proceed depends on a number of things. Is the OP just trying to use the computer or is there files that need to be retrieved? If they are just reclaiming a computer for use and there is no need for file recovery, reinstall the operating system. If it is a fairly recent vintage laptop there may not have been an installation disc. More often the installation files are on a partition of the hard drive in the computer. Each manufacturer has their own procedure to access that partition to do a fresh install. Best place to get that info is the support message boards for that make of computer. 

If there are files that need to be recovered, Disco Stu's plan is a solid one. If the OP doesn't want to do that or there are encrypted files on the computer, best to bring it to a recovery specialist. Be clear in what needs to be done and keep in mind that it might be expensive. Good luck.