The engine and the transmission always needs to be warmed up, before l take it to drive. Even on a hot summer day. Do you think changing the transmission fluid and filter might help. Operator is manual says that 528l has a lifetime transmission fluid in it. That means you will never have to replace the fluid??? Please help. Thanks

You have not been clear on the problem with ur tranny leading u to warm it up first.
l think that when BMW says ''lifetime oil it means up to the point where they no longer r responsible for whatever happens to the transmission.
For a ten year old car, with presumably high mileage, then go ahead & replace the fluid. But use the recommended oil
and nothing else . Do not use ATF no matter what others say.
Do not flush the tranny. Either just drain & replace the oil
(see previous posts on this topic, l am tired of repeating the same procedure over & over again), or remove the tranny oil pan, clean it, clean or replace the filter, then refill. l repeat, follow proper procedures.
l do not know if changing the oil would correct ur problem, but it is at least worth the try.