Land owner with a bad lease

I could use some advice.

My father died this year and had recently signed what I believe is a poor land lease for a two sided sign on a major interstate.

The lease states it is binding on the heirs. However, an attorney reviewed the lease and noted it is poorly written and only describes the land being rented as being x numbers of miles south of a city facing the interstate north and south.

Each side rents for 1100 -1500 per month. The 10 year agreement pays 1500 per year and increases to 2000 at the end of decade.

The company who owns the sign has a left a message that they will send me a new lease to sign.

Any tips on how to proceed? This sign has been on our property for decades. Prior to 2010 the rent had only been 200 per year.

Thank you in advance

bigsign