How to replace Tank Water Heater with a Tankless Electric Water Heater

The parts I used for this install are:

1) One (1) - Rheem Performance 27 (RETEX-27) 5.27 GPM Tankless Electric Water Heater @ $559.00ea - $559.00
https://www.homedepot.com/p/Rheem-Per...

2) One (1) - Southwire 125 ft. 8/2 Black Stranded Romex SIMpull CU NM-B W/G Wire @ $279.00ea - $279.00
https://www.homedepot.com/p/Southwire...

3) One (1) - Carlon 1 in. x 25 ft. Electrical Nonmetallic Tubing Conduit Coil, Blue @ $43.86ea - $43.86
https://www.homedepot.com/p/Carlon-1-...

4) One (1) - Carlon 1 in. ENT Male Adapter (Standard Fitting) @ $2.92ea - $2.92
https://www.homedepot.com/p/Carlon-1-...

5) One (1) - Halex 1-1/2 in. x 1 in. Rigid Conduit Reducing Washer (4-Pack) @ $2.71ea - $2.71
https://www.homedepot.com/p/Halex-1-1...

6) One (1) - Halex 1 in. Rigid Conduit Locknut (2-Pack) @ $0.93ea - $0.93
https://www.homedepot.com/p/Halex-1-i...

7) Three (3) - Siemens 40 Amp Double-Pole Type QP Circuit Breaker @ $16.98ea - $50.94
https://www.homedepot.com/p/Siemens-4...

8) One (1) - Dielectric Nipple Heat Trap (2-Piece) @ $12.98ea - $12.98
https://www.homedepot.com/p/Everbilt-...

9) One (1) - Dielectric Nipple (2-Piece) @ 5.98ea - $5.98
https://www.homedepot.com/p/Everbilt-...

10) Two (2) - SharkBite 3/4 in. Push-to-Connect x 3/4 in. FIP x 24 in. Braided Stainless Steel Water Heater Connector @ $19.45 - $38.90
https://www.homedepot.com/p/SharkBite...

11) One (1) - Commercial Electric Winged Wire Connectors, Green (15-Pack) @ $3.98ea - $3.98
https://www.homedepot.com/p/Commercia...

12) One (1) - Klein Tools Compact Cable Cutter @ $21.97ea - $21.97
https://www.homedepot.com/p/Klein-Too...

13) One (1) - Blue Monster 3/4 in. x 1429 in. PTFE Thread Seal Tape @ $4.84ea - $4.84
https://www.homedepot.com/p/Blue-Mons...

14) One (1) - HOME-FLEX 3/4 in. FIP x 3/4 in. FIP 24 in. Stainless Steel Corrugated Water Heater Connector (2-Piece) @ $31.48 - $31.48
https://www.homedepot.com/p/HOME-FLEX...

15) One (1) - Anvil 18 mm and 9 mm Snap-Off Knife Set (2-Piece) @ $2.97ea - $2.97
https://www.homedepot.com/p/Anvil-18-...

15) One (1) - AmazonCommercial Vinyl Electrical Tape, 3/4 in x 60 ft x 0.007in (19 mm x 18.3 m x 0.18mm), Red, (12-Pack) @ $10.80 - $10.80
https://www.amazon.com/gp/product/B08...

17) One (1) - Twinkle Star 3/4 Inch IPS Isolator Tankless Water Heater Service Valve Kit, with Pressure Relief Valve, Clean Brass Construction @ $59.99ea - $59.99
https://www.amazon.com/dp/B085Q8DL8B?...

Total Cost before tax: $1,133.25
Sales tax (6.5%): 73.66
Total after tax: $1,206.92

You may not need the exact same things I needed (may need different sizes), you also may already have some of the tools and parts on hand.