Strong acid can cleave the complexes e.g. HCl /H20 in diglyme. see below. Sodium methoxide in diglyme liberates an Amine from an Amine Borane compelx.

Acidic hydrolysis leads to an Amine hydrochloride.

see

Brown, Murray, Inorg. Chem. 1984, pp 2746-2753

Thank you Matthew, for the useful information

thank you Jagadeesh, for your valuable references

We were used to add HCl/MeOH and heat until dryness, maybe repeating the procedure 2-3 times. Our complex was indeed very strong. 

Dear

Sudhakar Yellapu

Using of HCl- H2O(1:1) with stirring for 1-2 hrs.,filtration, washing with water is very useful in such case.

Good luck