Degree of difficulty of filing and paying for inheritance tax

Want to ask how difficult it is for an heir to file and pay for inheritance tax? The estate consists of a condominium (mansion) and cash held in bank accounts. The estate value is over the 30 million yen threshold.

I believe assessment of value on the real estate has already been completed.

Would appreciate any advice on whether this is straightforward and something I could manage with N2 or possibly N1 level Japanese, or if a zeirishi is needed.

Many thanks in advance for any advice.