Tektronix Applications Expert

If by front cover you mean the protective front cover that comes on the unit, note the following: Standing in front of the scope grab in the center (middle) on both sides of the cover pull out then towards you or away from the scope.
If not see the link below to the service manual on tek.com
https://www.tek.com/en/manual/oscilloscope/6-series-mixed-signal-oscilloscope-service-manual-6-series-b-mso-mixed-signal-oscilloscope

Yes, the MDO3 Series is capable of field bandwidth upgrades. Option SUP3 BW2T34 will upgrade your MDO34 from 200MHz to 350MHz. Please reach out to buy@tektronix.com for the most accurate pricing information.

This information can be found on tek.com at this link https://www.tek.com/en/services/repair/warranty-status-search.
12 Months is recommended but it's up to the customers' use case.

You can change the display persistence by double-tapping in the Waveform View area to pull up the display menu. There are a couple options for persistence length, including variable and infinite. Variable persistence allows you to input the amount of time waveforms will collect on the screen. If you want to save a waveform file with a similar view, you can use the Envelope acquisition mode. This mode shows the extremes in variations over several waveform acquisitions. This mode can be found in the Acquisition menu.

The user manual is a pretty good place to start learning about the MSO68B: https://www.tek.com/en/manual/oscilloscope/456-series-mso-help-5-series-mso.

You can find videos on how to use the MSO68B on the following web page under the videos tab.

https://www.tek.com/en/products/oscilloscopes/6-series-mso

All the software on the disk should be on tek.com for free download.
However, there are newer versions available. Best bet is to search tek.com by model TDS1002. Manuals and software will be found there.

Replacement part information can be found in the user manual, but here is some info about the probes:
Probe tips: The rigid tip (gray tip) is pre-installed on the TPP0250 probe. The pogo tip (white tip) is pre-installed
on the TPP0500B probe, and is spring-loaded for compliant testing of circuitboards. Reorder numbers:
206-0649-xx (rigid tip)
206-0650-xx (pogo tip)
If you are interested in placing order or parts pricing, please reach out to our sales at 1.800.833.9200 option 1 or email the request to buy@tektronix.com.

The AFG31102 does not come with a rack mount kit. But, here's the product number for rack mount kit that can be purchased: AFG31000-RMK.

You cannot connect a TBS2000 directly to a computer. However you can save screenshots to a USB drive and print from that.

Here is a link to the declassification manual.

https://www.tek.com/en/oscilloscope/3-series-mdo-mixed-domain-oscilloscope-manual/3-series-mixed-domain-oscilloscope-0