I have a client who wants to terminate their existing SARSEP plan, replacing it with a 401(k) plan. I have not had alot of experience w/ SARSEP's, so please provide any input on the required procedures relative to termination. Thanks.

Ths can be done. The contributions to the SARSEP reduce the P/S deduction limits. The top-heavy rules have to be satisfied if either plan is top-heavy. Aggregate 402(g) limits apply for the year. Hope this helps.

Bear in mind that the employer should notify the employees of the intent to terminate SARSEP. The IRS recommends notifying the financial institution as well (I don’t understand why)…it appears there are no other termination requirements.
The employer may also check the plan document regarding any termination procedures.