What is the management of mild indentment of l4/l5?

Exercise . I presume you mean bulge of the l45 disc. This is normal finding with aging. Exercise and learning proper posture and body mechanics will usually control most low pain caused by bulging discs.
Exercises. A bulge of the disc at the l4-5 level is a normal findings for people 39 years or older. This can be managed by staying active. Exercises that target the core muscles will be important in helping to maintain proper posture and balance.