The reason the built-in battery should not be replaced is that it has a special connector that any damage to is not covered by warranty. My MacBook is a 2009 one, so the warranty has expired. So does a "Replace Soon" battery = a bad battery? And how can the battery be replaced with an expired warranty?
Why do you think it shouldn't be replaced. If it is telling you to replace soon that mean it needs to be replaced.
Any apple store can do that for you and it comes with a limited warranty. That special connector is something any apple store deals with daily. So I would assume they know exacty how to disconnect it and reconnect it without causing any damage.
Mac Help told me to use the computer on battery power until it is below 95%, then I plug back in to charge to 100% and it works.
OK, here is the system profile for Power under Battery Information:
Serial Number: W0945119A77ZC
Device name: bq20z451
Pack Lot Code: 0000
PCB Lot Code: 0000
Firmware Version: 0003
Hardware Revision: 0002
Cell Revision: 0100
Charge remaining (mAh): 2572
Fully charged: No
Full charge capacity (mAh): 2625
Cycle count: 1016
Condition: Replace Soon
Battery Installed: Yes
Amperage (mA): 452
Voltage (mV): 12571
Sorry but I don't see what the problem is with changing out the battery. The system is telling you it needs to be replaced. All batteries only last so long. Yours is 4 years old and all reports state it needs to be replaced.
If you do a search for replace macbook pro battery I'm sure the suggested price would come up. Or you could call your local apple store and ask them.
Batteries aren't really covered under the warranty anyway. Unless the system is nearly new and the battery fails. So it would always be at the owner expense to replace it. Most all apple stores do this regularly so they would know exactly what it will cost you.
Battery Cycle Count /Battery Life
Battery Replacement > How much does battery replacement cost?