Staff at Dyer Burdett and Co called in the police after Russell Ormerod began the protest at the Havant firm last week.
The 33-year-old from New Road, Portsmouth, bought a set of handcuffs in a sex shop and was driven to the office in West Street, on Thursday afternoon.
Mr Ormerod and his three older brothers are currently involved in a long-running dispute with the firm over the settlement of their father's will.
John Ormerod died in March last year aged 86 and the brothers claimed they were each owed £5,000 by the firm after his estate had been settled.
Russell Ormerod telephoned the legal firm to tell staff of his plan to protest outside the office.
On his arrival a cheque was drawn for him.
But he handcuffed himself to the glass doors anyway, just after 1pm.
Police officers were called to the address and turned up with a set of bolt-croppers after Mr Ormerod told staff he did not have the key.
He said: 'I think the police were really good. They said to me that they realised I was just making a peaceful protest but they had to move me on.
'I was there about an hour all together and although I have probably made myself look a bit stupid I have at last been listened to.
'I was at the end of my tether because this dispute has been going on for years and I wanted to finally get something done about it.
'I will be taking further action regarding my dad's will.'
Shoppers walking past the offices opposite Havant's main shopping area gathered to watch the situation unfold. After Mr Ormerod was released he was driven away.
The News tried to speak with the firm and discuss the matter but no-one was prepared to elaborate on what happened.
Michael Dyer, one of the firm's directors, said: 'I have absolutely no comment.'